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.

Showing 1-3 of 3 results.

A131056 A007318 * A131055.

Original entry on oeis.org

1, 3, 7, 17, 41, 97, 225, 513, 1153, 2561, 5633, 12289, 26625, 57345, 122881, 262145, 557057, 1179649, 2490369, 5242881, 11010049, 23068673, 48234497, 100663297, 209715201, 436207617, 905969665
Offset: 1

Views

Author

Gary W. Adamson, Jun 12 2007

Keywords

Examples

			a(4) = 17 = (1, 3, 3, 1) dot (1, 2, 2, 4) = (1 + 6 + 6 + 4).
		

Crossrefs

Programs

Formula

Binomial transform of A131055: (1, 2, 2, 4, 4, 6, 6, ...). A131056 = A131054 as an infinite lower triangular matrix * [1,2,3,...] as a vector.
G.f.: x*(1-2*x+2*x^3)/((1-x)*(1-2*x)^2); a(n)=-0^n/2+2^(n-1)*(n+1)+1. - Paul Barry, Jun 14 2008
a(n) = 2+A099035(n-1), n>1. - Juri-Stepan Gerasimov, Oct 02 2011

Extensions

More terms from Paul Barry, Jun 14 2008

A173398 (A007318 + A112468)/2.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 4, 2, 1, 1, 1, 7, 4, 3, 1, 1, 1, 11, 7, 9, 3, 1, 1, 1, 16, 11, 22, 9, 4, 1, 1, 1, 22, 16, 46, 22, 16, 4, 1, 1, 1, 29, 22, 86, 46, 50, 16, 5, 1, 1, 1, 37, 29, 148, 86, 130, 50, 25, 5, 1
Offset: 1

Views

Author

Mark Dols, Feb 17 2010, Feb 21 2010

Keywords

Comments

If first row is omitted,same as A131054.

Examples

			Array starts:
1,1,1,1
1,1,2,2
1,1,4,4
1,1,7,7
		

Crossrefs

A173402 (A007318 - A112468)/2.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, 2, 1, 0, 0, 3, 2, 2, 0, 0, 4, 3, 6, 2, 0, 0, 5, 4, 13, 6, 3, 0, 0, 6, 5, 24, 13, 12, 3, 0, 0, 7, 6, 40, 24, 34, 12, 4, 0, 0, 8, 7, 62, 40, 80, 34, 20, 4, 0, 0, 9, 8, 91, 62, 166, 80, 70, 20, 5, 0, 0, 10, 9, 128, 91, 314, 166, 200, 70, 30, 5, 0
Offset: 1

Views

Author

Mark Dols, Feb 17 2010

Keywords

Comments

Same as A131053, but with additional row/column of zeros.

Examples

			Array starts:
0,0,0,0
0,1,1,2
0,2,2,6
0,3,3,13
		

Crossrefs

Showing 1-3 of 3 results.