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A113678 Sequence array for A078008. 1
1, 0, 1, 2, 0, 1, 2, 2, 0, 1, 6, 2, 2, 0, 1, 10, 6, 2, 2, 0, 1, 22, 10, 6, 2, 2, 0, 1, 42, 22, 10, 6, 2, 2, 0, 1, 86, 42, 22, 10, 6, 2, 2, 0, 1, 170, 86, 42, 22, 10, 6, 2, 2, 0, 1, 342, 170, 86, 42, 22, 10, 6, 2, 2, 0, 1, 682, 342, 170, 86, 42, 22, 10, 6, 2, 2, 0, 1, 1366, 682, 342, 170, 86 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Row sums are A001045(n+1). Diagonal sums are A053088. Inverse is A113680.

LINKS

Table of n, a(n) for n=0..82.

FORMULA

Riordan array ((1-x)/(1-x-2x^2), x); Number triangle T(n, k)=if(k<=n, (2^(n-k)+2(-1)^(n-k))/3, 0); T(n, k)=sum{i=0..n, C(n-i, k)C(k, n-i)(2^i+2(-1)^i)/3}.

EXAMPLE

Triangle begins

1;

0, 1;

2, 0, 1;

2, 2, 0, 1;

6, 2, 2, 0, 1;

10, 6, 2, 2, 0, 1;

22, 10, 6, 2, 2, 0, 1;

CROSSREFS

Sequence in context: A096144 A118401 A147767 * A305436 A299480 A110249

Adjacent sequences:  A113675 A113676 A113677 * A113679 A113680 A113681

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry, Nov 04 2005

STATUS

approved

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Last modified October 15 15:14 EDT 2019. Contains 328030 sequences. (Running on oeis4.)