A134350 Row sums of triangle A134349.

1, 7, 23, 67, 191, 547, 1583, 4627, 13631, 40387, 120143, 358387, 1071071, 3205027

Offset

1,2

Links

Table of n, a(n) for n=1..14.

Index entries for linear recurrences with constant coefficients, signature (6, -11, 6).

Formula

Binomial transform of A134351 and double binomial transform of [1, 5, -1, 5, -1, 5, -1, 5, ...].

Conjecture from Colin Barker, Mar 13 2014: (Start)

a(n) = 2^n + 2*3^(n-1) - 3.

a(n) = 5*a(n-1) - 5*a(n-2) - 5*a(n-3) + 6*a(n-4).

G.f.: x*(8*x^2-x-1) / ((x-1)*(2*x-1)*(3*x-1)).

(End)

Example

a(3) = 23 = sum of row 3 terms of triangle A134349: (2 + 8 + 13).
a(3) = 23 = (1, 2, 1) dot (1, 6, 10) = (1 + 12 + 10), where A134351 = (1, 6, 10, 128, 34, 66, ...).

Crossrefs

Cf. A134349, A134351.

Sequence in context: A297315 A048457 A048458 * A005342 A139852 A141194

Adjacent sequences: A134347 A134348 A134349 * A134351 A134352 A134353

Keyword

nonn,more

Author

Gary W. Adamson, Oct 21 2007

Status

approved