A276517 Indices k such that A276516(k) = 0.

2, 3, 6, 7, 8, 11, 12, 15, 18, 19, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 41, 43, 44, 45, 46, 47, 48, 53, 54, 60, 61, 67, 70, 72, 74, 76, 79, 82, 84, 87, 90, 92, 93, 96, 105, 106, 107, 108, 111, 112, 114, 117, 122, 128, 133, 135, 139, 141, 148, 159

Offset: 1

Author

Vaclav Kotesovec, Dec 12 2016

Keywords

• nonn

Comments

This is different from A001422, first difference: a(14) = 25, A001422(14) = 27.

Conjecture: for k > 7169 there are no more terms in this sequence (tested for k < 10000000).

Examples

			3 is in the sequence because A276516(3) = 0
4 is not in the sequence because A276516(4) = -1
4222 is in the sequence because A276516(4222) = 0
7169 is in the sequence because A276516(7169) = 0
		

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 1..173

Crossrefs

Cf. A001422, A001661, A276516, A279486, A279487.

Programs

Mathematica

nn = 100; A276516 = Rest[CoefficientList[Series[Product[(1-x^(k^2)), {k, nn}], {x, 0, nn^2}], x]]; Select[Range[nn^2], A276516[[#]]==0&]
nmax = 10000; nn = Floor[Sqrt[nmax]]+1; poly = ConstantArray[0, nn^2 + 1]; poly[[1]] = 1; poly[[2]] = -1; poly[[3]] = 0; Do[Do[poly[[j + 1]] -= poly[[j - k^2 + 1]], {j, nn^2, k^2, -1}];, {k, 2, nn}]; A276516 = Take[poly, {2, nmax+1}]; Select[Range[nmax], A276516[[#]]==0&]