cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A298983 Triangle read by rows T(n,k) giving coefficients in expansion of Product_{j=1..n} (1-x^j)^2 mod x^(n+1)-1.

Original entry on oeis.org

1, 2, -2, 6, -3, -3, 8, 0, -8, 0, 20, -5, -5, -5, -5, 12, 6, -6, -12, -6, 6, 42, -7, -7, -7, -7, -7, -7, 32, 0, 0, 0, -32, 0, 0, 0, 54, 0, 0, -27, 0, 0, -27, 0, 0, 40, 10, -10, 10, -10, -40, -10, 10, -10, 10, 110, -11, -11, -11, -11, -11, -11, -11, -11, -11, -11
Offset: 0

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Author

Seiichi Manyama, Mar 10 2018

Keywords

Examples

			Triangle begins:
  k   0    1    2    3    4    5    6
n
0     1;
1     2,  -2;
2     6,  -3,  -3;
3     8,   0,  -8,   0;
4    20,  -5,  -5,  -5,  -5;
5    12,   6,  -6, -12,  -6,   6;
6    42,  -7,  -7,  -7,  -7,  -7,  -7;
		

Crossrefs

Formula

T(n,k) = (n+1) * Sum_{d | gcd(n+1,n+1-k)} d*mu((n+1)/d) for 0 <= k <= n.
So T(n,0) = A002618(n+1) and T(n,n) = A055615(n+1).