login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A032187 Shifts left 3 places under "CIJ" (necklace, indistinct, labeled) transform. 1
1, 1, 1, 1, 2, 6, 26, 151, 1093, 9489, 96084, 1111722, 14469388, 209234595, 3328056991, 57746229265, 1085448899206, 21972175778646, 476535125344462, 11024061833485335, 270965694793159153, 7051933526740491393, 193723061625591928384, 5601822117610355927946 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..200

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. - 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. - 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); /* Vladimir Kruchinin, May 10 2011 */

(PARI)

CIJ(p)={-log(1-p)}

seq(n)={my(p=x+x^2+O(x*x^(n%3))); for(i=1, n\3, p=intformal(1 + intformal(1 + intformal(1 + CIJ(p))))); Vec(serlaplace(p))} \\ Andrew Howroyd, Sep 19 2018

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

EXTENSIONS

Terms a(22) and beyond from Andrew Howroyd, Sep 19 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 15 20:40 EDT 2018. Contains 316237 sequences. (Running on oeis4.)