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A107113 Diagonal sums of A107111, viewed as a number triangle. 1
1, 1, 2, 3, 6, 11, 24, 52, 125, 307, 809, 2190, 6249, 18348, 56016, 176272, 571113, 1906091, 6517283, 22879944, 82144248, 301617448, 1131401427, 4327790902, 16886037207, 67073179408, 271242546501, 1115489848809, 4662462489619 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..28.

FORMULA

a(n)=sum{k=0..floor(n/2), sum{j=0..k, binomial((n-2k)(k+1), k-j)*binomial(k+j, j)}/(k+1)}

CROSSREFS

Sequence in context: A122852 A192573 A284994 * A156807 A032256 A324765

Adjacent sequences:  A107110 A107111 A107112 * A107114 A107115 A107116

KEYWORD

easy,nonn

AUTHOR

Paul Barry, May 12 2005

STATUS

approved

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Last modified January 28 23:12 EST 2022. Contains 350670 sequences. (Running on oeis4.)