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A032187 Shifts left 3 places under "CIJ" (necklace, indistinct, labeled) transform. 0
1, 1, 1, 1, 2, 6, 26, 151, 1093, 9489, 96084, 1111722, 14469388, 209234595, 3328056991, 57746229265, 1085448899206, 21972175778646, 476535125344462, 11024061833485335, 270965694793159153 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Table of n, a(n) for n=1..21.

FORMULA

a(n)=sum(k=0..n-5, binomial(n-4,k)*a(k+4)*a(n-k-4))+a(n-3), n>4, a(1)=a(2)=a(3)=a(4)=1. [From Vladimir Kruchinin, May 10 2011]

E.g.f. A(x) satisfies differential equation A'''(x)=log(1/(1-A(x))), A'(0)=1, A''(0)=1, A'''(0)=1. [From Vladimir Kruchinin, Nov 19 2011]

PROG

(Maxima)

a(n):=if n=0 then 0 else if n<5 then 1 else sum(binomial(n-4, k)*a(k+4)*a(n-k-4), k, 0, n-5)+a(n-3); [From Vladimir Kruchinin, May 10 2011]

CROSSREFS

Sequence in context: A159311 A000629 A185994 * A003659 A159602 A032271

Adjacent sequences:  A032184 A032185 A032186 * A032188 A032189 A032190

KEYWORD

nonn,eigen

AUTHOR

Christian G. Bower

STATUS

approved

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Last modified February 20 11:03 EST 2018. Contains 299385 sequences. (Running on oeis4.)