A115282 Correlation triangle for the sequence 3-2*0^n.

1, 3, 3, 3, 10, 3, 3, 12, 12, 3, 3, 12, 19, 12, 3, 3, 12, 21, 21, 12, 3, 3, 12, 21, 28, 21, 12, 3, 3, 12, 21, 30, 30, 21, 12, 3, 3, 12, 21, 30, 37, 30, 21, 12, 3, 3, 12, 21, 30, 39, 39, 30, 21, 12, 3, 3, 12, 21, 30, 39, 46, 39, 30, 21, 12, 3

Offset

0,2

Comments

Row sums are A102214. Diagonal sums are A115283. T(2n,n) is 9n+1 (A017173), the partial sums of (3-2*0^n)^2. T(2n,n)-T(2n,n+1) is 7-6*0^n.

Links

Table of n, a(n) for n=0..65.

Formula

G.f.: (1+2x)(1+2x*y)/((1-x)(1-x*y)(1-x^2*y)); Number triangle T(n, k)=sum{j=0..n, [j<=k]*(3-2*0^(k-j))*[j<=n-k]*(3-2*0^(n-k-j))}.

Example

Triangle begins
1;
3, 3;
3,10, 3;
3,12,12, 3;
3,12,19,12, 3;
3,12,21,21,12, 3;
3,12,21,28,21,12,3;

Crossrefs

Sequence in context: A160589 A097707 A240533 * A370193 A321507 A147605

Adjacent sequences: A115279 A115280 A115281 * A115283 A115284 A115285

Keyword

easy,nonn,tabl

Author

Paul Barry, Jan 19 2006

Status

approved