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A127059 Column 2 of triangle A127058. +0
3
3, 12, 108, 1332, 19908, 342252, 6583788, 139380372, 3211960068, 79950396492, 2137119431148, 61065403377012, 1858069709657028, 60006976422450732, 2050924514408985708, 73988085260209757652, 2810535115787602525188 (list; graph; listen)
OFFSET

0,1

COMMENT

Column 0 of triangle A127059 is A000698, the number of shellings of an n-cube, divided by 2^n n!. Column 1 of triangle A127059 is A115974, the number of Feynman diagrams of the proper self-energy at perturbative order n.

FORMULA

a(0)=3 and for n>0 a(n)=(1/2)*(c(n+3)-3*c(n+2)-sum(a(k)*(c(n+2-k)-c(n+1-k)),k=0..n-1) with c(n)=(2*n)!/(2^n*n!) [From Groux roland (roland.groux(AT)orange.fr), Nov 14 2009]

CROSSREFS

Cf. A127058; other columns: A000698, A115974; A127060.

Sequence in context: A141535 A111485 A080447 this_sequence A068099 A032113 A119649

Adjacent sequences: A127056 A127057 A127058 this_sequence A127060 A127061 A127062

KEYWORD

nonn

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Jan 04 2007

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Last modified December 13 23:45 EST 2009. Contains 170824 sequences.


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