A279487 Indices k such that A279485(k) = 0.

2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70

Offset: 1

Author

Vaclav Kotesovec, Dec 13 2016

Keywords

• nonn

Comments

This is different from A046039, first difference: a(14328) = 14979, A046039(14328) = 14981.

Conjecture: Last term is a(1040799) = 64674419. For k > 64674419 there are no more terms in this sequence (tested for k < 150000000).

Last terms are: 30082710, 30345655, 30358709, 30530388, 30982210, 31463972, 32369456, 32374194, 32594966, 32658048, 32780596, 32875172, 32997892, 33135812, 33440935, 33647428, 34086978, 34112787, 34629875, 35535908, 35638453, 36081828, 36140868, 36945332, 39218566, 39581363, 40364547, 40491526, 41235157, 43853600, 47973011, 57353782, 57767766, 64674419

Examples

			3 is in the sequence because A279485(3) = 0
16 is not in the sequence because A279485(16) = -1
57767766 is in the sequence because A279485(57767766) = 0
64674419 is in the sequence because A279485(64674419) = 0
		

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 1..100000

Crossrefs

Cf. A001661, A046039, A279485.

Cf. A276517, A279486.

Programs

Mathematica

nn = 10; A279485 = Rest[CoefficientList[Series[Product[(1-x^(k^4)), {k, nn}], {x, 0, nn^4}], x]]; Select[Range[nn^4], A279485[[#]]==0&]
nmax = 10000; nn = Floor[nmax^(1/4)]+1; poly = ConstantArray[0, nn^4 + 1]; poly[[1]] = 1; poly[[2]] = -1; poly[[3]] = 0; Do[Do[poly[[j + 1]] -= poly[[j - k^4 + 1]], {j, nn^4, k^4, -1}];, {k, 2, nn}]; A279485 = Take[poly, {2, nmax+1}]; Select[Range[nmax], A279485[[#]]==0&]