A113046 Diagonal sums of number triangle binomial(n, floor((n-k)/2)) mod 3.

1, 1, 3, 1, 1, 3, 5, 5, 6, 3, 3, 3, 3, 3, 3, 1, 1, 9, 11, 11, 12, 5, 5, 15, 16, 10, 12, 6, 6, 9, 9, 6, 6, 3, 3, 9, 9, 9, 9, 3, 3, 9, 9, 6, 6, 3, 3, 3, 3, 3, 3, 1, 1, 27, 29, 29, 30, 11, 11, 33, 34, 22, 24, 12, 12, 15, 15, 12, 12, 5, 5, 45, 46, 28, 30, 16, 16, 30, 32, 23, 24, 12, 12, 18, 18, 12

Offset

0,3

Comments

Diagonal sums of A113045.

Links

Antti Karttunen, Table of n, a(n) for n = 0..10000

Formula

a(n) = Sum_{k=0..floor(n/2)} binomial(n-k, floor((n-2k)/2)) mod 3.

Maple

A113046:=n->add(binomial(n-k, floor((n-2*k)/2)) mod 3, k=0..floor(n/2)): seq(A113046(n), n=0..150); # Wesley Ivan Hurt, Jul 25 2017

Prog

(PARI) A113046(n) = sum(k=0, n\2, binomial(n-k, ((n-(2*k))\2))%3); \\ Antti Karttunen, Jul 24 2017

Crossrefs

Cf. A113045.

Sequence in context: A016599 A079650 A094644 * A245541 A209563 A308624

Adjacent sequences: A113043 A113044 A113045 * A113047 A113048 A113049

Keyword

easy,nonn

Author

Paul Barry, Oct 11 2005

Status

approved