The On-Line Encyclopedia of Integer Sequences (OEIS)

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A113049

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

#3 by Russ Cox at Fri Mar 30 18:59:12 EDT 2012

AUTHOR

_Paul Barry (pbarry(AT)wit.ie), _, Oct 11 2005

Discussion

Fri Mar 30

18:59

OEIS Server: https://oeis.org/edit/global/287

#2 by N. J. A. Sloane at Fri Feb 24 03:00:00 EST 2006

FORMULA

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

KEYWORD

easy,nonn,tabl,new

#1 by N. J. A. Sloane at Tue Jan 24 03:00:00 EST 2006

NAME

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

DATA

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

OFFSET

0,1

COMMENTS

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

FORMULA

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

EXAMPLE

Rows begin

3;

11, 13;

43, 45, 53;

171, 173, 181, 213;

683, 685, 693, 725, 683;

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

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Oct 11 2005

STATUS

approved