David Speyer's solution to Pell's equation P^2-DQ^2 = 1 in polynomials, where D(0) = n; tabulated for n <= 100 ============================================================================================================== n = 1: perfect square n = 2: D = 4x^2+6x+2, P = 4x+3, Q = 2 n = 3: D = x^2+4x+3, P = x+2, Q = 1 n = 4: perfect square n = 5: D = 16x^2+18x+5, P = 16x+9, Q = 4 n = 6: D = 4x^2+10x+6, P = 4x+5, Q = 2 n = 7: D = 9x^2+16x+7, P = 9x+8, Q = 3 n = 8: D = x^2+6x+8, P = x+3, Q = 1 n = 9: perfect square n = 10: D = 36x^2+38x+10, P = 36x+19, Q = 6 n = 11: D = 9x^2+20x+11, P = 9x+10, Q = 3 n = 12: D = 4x^2+14x+12, P = 4x+7, Q = 2 n = 13: D = 32400x^2+1298x+13, P = 32400x+649, Q = 180 n = 14: D = 16x^2+30x+14, P = 16x+15, Q = 4 n = 15: D = x^2+8x+15, P = x+4, Q = 1 n = 16: perfect square n = 17: D = 64x^2+66x+17, P = 64x+33, Q = 8 n = 18: D = 16x^2+34x+18, P = 16x+17, Q = 4 n = 19: D = 1521x^2+340x+19, P = 1521x+170, Q = 39 n = 20: D = 4x^2+18x+20, P = 4x+9, Q = 2 n = 21: D = 144x^2+110x+21, P = 144x+55, Q = 12 n = 22: D = 1764x^2+394x+22, P = 1764x+197, Q = 42 n = 23: D = 25x^2+48x+23, P = 25x+24, Q = 5 n = 24: D = x^2+10x+24, P = x+5, Q = 1 n = 25: perfect square n = 26: D = 100x^2+102x+26, P = 100x+51, Q = 10 n = 27: D = 25x^2+52x+27, P = 25x+26, Q = 5 n = 28: D = 576x^2+254x+28, P = 576x+127, Q = 24 n = 29: D = 3312400x^2+19602x+29, P = 3312400x+9801, Q = 1820 n = 30: D = 4x^2+22x+30, P = 4x+11, Q = 2 n = 31: D = 74529x^2+3040x+31, P = 74529x+1520, Q = 273 n = 32: D = 9x^2+34x+32, P = 9x+17, Q = 3 n = 33: D = 16x^2+46x+33, P = 16x+23, Q = 4 n = 34: D = 36x^2+70x+34, P = 36x+35, Q = 6 n = 35: D = x^2+12x+35, P = x+6, Q = 1 n = 36: perfect square n = 37: D = 144x^2+146x+37, P = 144x+73, Q = 12 n = 38: D = 36x^2+74x+38, P = 36x+37, Q = 6 n = 39: D = 16x^2+50x+39, P = 16x+25, Q = 4 n = 40: D = 9x^2+38x+40, P = 9x+19, Q = 3 n = 41: D = 102400x^2+4098x+41, P = 102400x+2049, Q = 320 n = 42: D = 4x^2+26x+42, P = 4x+13, Q = 2 n = 43: D = 281961x^2+6964x+43, P = 281961x+3482, Q = 531 n = 44: D = 900x^2+398x+44, P = 900x+199, Q = 30 n = 45: D = 576x^2+322x+45, P = 576x+161, Q = 24 n = 46: D = 12873744x^2+48670x+46, P = 12873744x+24335, Q = 3588 n = 47: D = 49x^2+96x+47, P = 49x+48, Q = 7 n = 48: D = x^2+14x+48, P = x+7, Q = 1 n = 49: perfect square n = 50: D = 196x^2+198x+50, P = 196x+99, Q = 14 n = 51: D = 49x^2+100x+51, P = 49x+50, Q = 7 n = 52: D = 8100x^2+1298x+52, P = 8100x+649, Q = 90 n = 53: D = 82810000x^2+132498x+53, P = 82810000x+66249, Q = 9100 n = 54: D = 4356x^2+970x+54, P = 4356x+485, Q = 66 n = 55: D = 144x^2+178x+55, P = 144x+89, Q = 12 n = 56: D = 4x^2+30x+56, P = 4x+15, Q = 2 n = 57: D = 400x^2+302x+57, P = 400x+151, Q = 20 n = 58: D = 6625476x^2+39206x+58, P = 6625476x+19603, Q = 2574 n = 59: D = 4761x^2+1060x+59, P = 4761x+530, Q = 69 n = 60: D = 16x^2+62x+60, P = 16x+31, Q = 4 n = 61: D = 51145622669840400x^2+3532638098x+61, P = 51145622669840400x+1766319049, Q = 226153980 n = 62: D = 64x^2+126x+62, P = 64x+63, Q = 8 n = 63: D = x^2+16x+63, P = x+8, Q = 1 n = 64: perfect square n = 65: D = 256x^2+258x+65, P = 256x+129, Q = 16 n = 66: D = 64x^2+130x+66, P = 64x+65, Q = 8 n = 67: D = 35605089x^2+97684x+67, P = 35605089x+48842, Q = 5967 n = 68: D = 16x^2+66x+68, P = 16x+33, Q = 4 n = 69: D = 876096x^2+15550x+69, P = 876096x+7775, Q = 936 n = 70: D = 900x^2+502x+70, P = 900x+251, Q = 30 n = 71: D = 170569x^2+6960x+71, P = 170569x+3480, Q = 413 n = 72: D = 4x^2+34x+72, P = 4x+17, Q = 2 n = 73: D = 71289000000x^2+4562498x+73, P = 71289000000x+2281249, Q = 267000 n = 74: D = 184900x^2+7398x+74, P = 184900x+3699, Q = 430 n = 75: D = 9x^2+52x+75, P = 9x+26, Q = 3 n = 76: D = 43956900x^2+115598x+76, P = 43956900x+57799, Q = 6630 n = 77: D = 1600x^2+702x+77, P = 1600x+351, Q = 40 n = 78: D = 36x^2+106x+78, P = 36x+53, Q = 6 n = 79: D = 81x^2+160x+79, P = 81x+80, Q = 9 n = 80: D = x^2+18x+80, P = x+9, Q = 1 n = 81: perfect square n = 82: D = 324x^2+326x+82, P = 324x+163, Q = 18 n = 83: D = 81x^2+164x+83, P = 81x+82, Q = 9 n = 84: D = 36x^2+110x+84, P = 36x+55, Q = 6 n = 85: D = 960752016x^2+571538x+85, P = 960752016x+285769, Q = 30996 n = 86: D = 1258884x^2+20810x+86, P = 1258884x+10405, Q = 1122 n = 87: D = 9x^2+56x+87, P = 9x+28, Q = 3 n = 88: D = 441x^2+394x+88, P = 441x+197, Q = 21 n = 89: D = 2809000000x^2+1000002x+89, P = 2809000000x+500001, Q = 53000 n = 90: D = 4x^2+38x+90, P = 4x+19, Q = 2 n = 91: D = 27225x^2+3148x+91, P = 27225x+1574, Q = 165 n = 92: D = 14400x^2+2302x+92, P = 14400x+1151, Q = 120 n = 93: D = 1587600x^2+24302x+93, P = 1587600x+12151, Q = 1260 n = 94: D = 48869292096x^2+4286590x+94, P = 48869292096x+2143295, Q = 221064 n = 95: D = 16x^2+78x+95, P = 16x+39, Q = 4 n = 96: D = 25x^2+98x+96, P = 25x+49, Q = 5 n = 97: D = 40670618531904x^2+125619266x+97, P = 40670618531904x+62809633, Q = 6377352 n = 98: D = 100x^2+198x+98, P = 100x+99, Q = 10 n = 99: D = x^2+20x+99, P = x+10, Q = 1 n = 100: perfect square