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A154324 Diagonal sums of number triangle A113582. 0
1, 1, 2, 3, 6, 12, 23, 43, 74, 124, 195, 300, 441, 637, 890, 1226, 1647, 2187, 2848, 3673, 4664, 5874, 7305, 9021, 11024, 13390, 16121, 19306, 22947, 27147, 31908, 37348, 43469, 50405, 58158, 66879, 76570, 87400, 99371, 112671, 127302 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..40.

Index to sequences with linear recurrences with constant coefficients, signature (3,0,-8,6,6,-8,0,3,-1).

FORMULA

G.f.: (1-2x-x^2+5x^3-x^4-2x^5+x^6)/((1-x)*(1-x^2))^3; a(n)=sum{k=0..floor(n/2), 1+C(k+1,2)*C(n-2k+1,2)}.

CROSSREFS

Sequence in context: A060985 A068012 A019138 * A001630 A164363 A103341

Adjacent sequences:  A154321 A154322 A154323 * A154325 A154326 A154327

KEYWORD

easy,nonn

AUTHOR

Paul Barry, Jan 07 2009

STATUS

approved

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Last modified April 18 11:22 EDT 2014. Contains 240707 sequences.