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.

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A188444 Expansion of (1+x)*(1+x+x^2)*(1-x+x^2-4*x+x^4-x^5+x^6)/(1+x^4)^3.

Original entry on oeis.org

1, 1, 1, -3, -9, -9, -6, 10, 25, 25, 15, -21, -49, -49, -28, 36, 81, 81, 45, -55, -121, -121, -66, 78, 169, 169, 91, -105, -225, -225, -120, 136, 289, 289, 153, -171, -361, -361, -190, 210, 441, 441, 231, -253, -529, -529, -276, 300, 625, 625, 325
Offset: 0

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Author

Paul Barry, Mar 31 2011

Keywords

Comments

a(n+1) is the Hankel transform of A166300(n+3) (diagonal sums of the triangle A100754).

Formula

G.f.: (1+x+x^2-3*x^3-6*x^4-6*x^5-3*x^6+x^7+x^8+x^9)/(1+x^4)^3.
a(n) = -3*a(n-4) - 3*a(n-8) - a(n-12). - Wesley Ivan Hurt, Mar 17 2023

A188461 A Deutsch-Fibonacci triangle.

Original entry on oeis.org

1, 1, 1, 1, 5, 1, 1, 10, 10, 1, 1, 16, 39, 16, 1, 1, 23, 99, 99, 23, 1, 1, 31, 203, 375, 203, 31, 1, 1, 40, 366, 1065, 1065, 366, 40, 1, 1, 50, 605, 2521, 4027, 2521, 605, 50, 1, 1, 61, 939, 5266, 12220, 12220, 5266, 939, 61, 1
Offset: 0

Views

Author

Paul Barry, Apr 01 2011

Keywords

Comments

Second column is A052905. Third column is A188480.

Examples

			Triangle begins
1,
1, 1,
1, 5, 1,
1, 10, 10, 1,
1, 16, 39, 16, 1,
1, 23, 99, 99, 23, 1,
1, 31, 203, 375, 203, 31, 1,
1, 40, 366, 1065, 1065, 366, 40, 1,
1, 50, 605, 2521, 4027, 2521, 605, 50, 1,
1, 61, 939, 5266, 12220, 12220, 5266, 939, 61, 1
		

Crossrefs

Formula

T(n,k)=sum{j=0..n-k+1, (j/(n+2-j))C(n+2-j,n-k+1)*C(n+2-j,k+1)*F(j+1)}.
Previous Showing 11-12 of 12 results.