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A131913 Product of the square matrix in A065941 and the column vector (1, 2, 3,...)'. 1
1, 3, 6, 13, 25, 48, 89, 163, 294, 525, 929, 1632, 2849, 4947, 8550, 14717, 25241, 43152, 73561, 125075, 212166, 359133, 606721, 1023168, 1722625, 2895843, 4861254, 8149933, 13646809, 22825200, 38136089, 63653827, 106146534, 176849517, 294401825, 489706272 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..35.

Index entries for linear recurrences with constant coefficients, signature (2,1,-2,-1).

FORMULA

Equals A010049(n) + A001629(n+2) and A055244(n) + A001629(n-1).

From Philippe Deléham, Dec 28 2013: (Start)

G.f.: (1+x-x^2)/(1-x-x^2)^2.

a(n) = 2*a(n-1)+a(n-2)-2*a(n-3)-a(n-4), a(0)=1, a(1)=3, a(2)=6, a(3)=13.

a(n) = a(n-1)+a(n-2)+2*Fibonacci(n). (End)

EXAMPLE

a(4) = 25 = (1, 1, 3, 2, 1) dot (1, 2, 3, 4, 5) = (1 + 2 + 9 + 8 + 5), where (1, 1, 3, 2, 1) = row 4 of triangle A065941.

a(4) = 25 = A010049(4) + A001629(6) = 5 + 20.

a(5) = 48 = A055244(6) + A001619(4) = 43 + 5.

CROSSREFS

Cf. A000045, A065941, A010049, A001629, A005244.

Sequence in context: A047194 A048039 A339617 * A182808 A285461 A324129

Adjacent sequences:  A131910 A131911 A131912 * A131914 A131915 A131916

KEYWORD

nonn,easy

AUTHOR

Gary W. Adamson, Jul 27 2007

STATUS

approved

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Last modified June 20 06:56 EDT 2021. Contains 345157 sequences. (Running on oeis4.)