A259914 Staircase path through the array P(n,k) of the k-th partial sums of cubes (A000578).
1, 9, 10, 46, 57, 203, 272, 846, 1200, 3432, 5082, 13728, 21021, 54483, 85696, 215254, 346086, 848198, 1388900, 3337236, 5549786, 13119614, 22108704, 51557260, 87885070, 202588830, 348817770, 796117860, 1382941125, 3129153795
Offset: 1
Examples
The array begins: [1], [9], 36, 100, 225, 441, ... A000537 1, [10], [46], 146, 371, 812, ... A024166 1, 11, [57], [203], 574, 1386, ... A101094 1, 12, 69, [272], [846], 2232, ... A101097 1, 13, 82, 354, [1200], [3432], ... A101102 1, 14, 96, 450, 1650, [5082], ... A254469
Programs
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Mathematica
Table[DifferenceRoot[Function[{a, n}, {(-650880 - 1496112*n - 1426512*n^2 - 722164*n^3 - 204716*n^4 - 30812*n^5 - 1924*n^6)*a[n] + (-56736 - 140412*n - 132006*n^2 - 58114*n^3 - 12090*n^4 - 962*n^5)*a[1 + n] + (78624 + 229884*n + 273800*n^2 + 167579*n^3 + 54567*n^4 + 8665*n^5 + 481*n^6)*a[2 + n] == 0, a[1] == 1, a[2] == 9}]][n], {n, 30}]
Formula
Conjecture: 2*(n+7)*(145672*n^2-236343*n+123525)*a(n) +(-78613*n^3-794662*n^2+327391*n+20220)*a(n-1) +2*(-582688*n^3-1889455*n^2-2148719*n-832650)*a(n-2) +4*(n-1)*(78613*n^2+133361*n+64050)*a(n-3) = 0. - R. J. Mathar, Jul 16 2015
Comments