login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A283331 a(n) = (Sum_{j=1..(K-1)/2} a(n-2*j+1)*a(n-2*j))/a(n-K) with a(1),...,a(K)=1, where K=7. 1
1, 1, 1, 1, 1, 1, 1, 3, 5, 17, 89, 1529, 136169, 208203929, 9450306981389, 393518208756305576259, 218756933853729911666129962011049, 967245356889229414311807903425793640476269370763657, 138385630187929719100558260443148868172248984484844599503721372030874017578780705 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,8

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..24

Matthew Christopher Russell, Using experimental mathematics to conjecture and prove theorems in the theory of partitions and commutative and non-commutative recurrences, PhD Dissertation, Mathematics Department, Rutgers University, May 2016; see also.

MATHEMATICA

a[n_]:=If[n<8, 1, Sum[a[n - 2j + 1]*a[n-2j], {j, 3}]/a[n - 7]]; Table[a[n], {n, 1, 20}] (* Indranil Ghosh, Mar 17 2017 *)

PROG

(PARI) a(n)= if(n<8, 1, sum(j=1, 3, a(n - 2*j + 1)*a(n - 2*j))/a(n - 7));

for(n=1, 20, print1(a(n), ", ")) \\ Indranil Ghosh, Mar 17 2017

CROSSREFS

Sequence in context: A281627 A102846 A100003 * A114161 A302199 A174722

Adjacent sequences:  A283328 A283329 A283330 * A283332 A283333 A283334

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Mar 17 2017

EXTENSIONS

More terms from Indranil Ghosh, Mar 17 2017

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 25 00:02 EDT 2020. Contains 337333 sequences. (Running on oeis4.)