A113049 - OEIS

A113049

Triangle of sums of Jacobsthal numbers related to binomial(4n,n)/(3n+1) mod 4.

3, 11, 13, 43, 45, 53, 171, 173, 181, 213, 683, 685, 693, 725, 853, 2731, 2733, 2741, 2773, 2901, 3413, 10923, 10925, 10933, 10965, 11093, 11605, 13653, 43691, 43693, 43701, 43733, 43861, 44373, 46421, 54613, 174763, 174765, 174773, 174805, 174933

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OFFSET

0,1

COMMENTS

First column is A007583(n+1). Main diagonal is A072197. Conjecture: A113048(n)=2 only if n=T(i,j).

LINKS

Table of n, a(n) for n=0..40.

FORMULA

T(n, k)=if(k<=n, J(2n+3)+2J(2k), 0), J(n)=A001045(n).

EXAMPLE

Rows begin

11, 13;

43, 45, 53;

171, 173, 181, 213;

683, 685, 693, 725, 683;

2731,2733, 2741, 2773, 2901, 3413;

CROSSREFS

Sequence in context: A168454 A181086 A274343 * A370425 A225097 A079665

Adjacent sequences: A113046 A113047 A113048 * A113050 A113051 A113052

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry, Oct 11 2005

STATUS

approved