The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A218379 Number of partitions of n into pentagonal parts. 11

%I #27 Dec 09 2017 20:27:26

%S 1,1,1,1,1,2,2,2,2,2,3,3,4,4,4,5,5,6,6,6,7,7,9,9,10,11,11,13,13,14,15,

%T 15,17,17,19,21,22,24,24,26,28,29,31,31,34,36,38,41,42,45,47,50,53,54,

%U 57,59,63,67,69,73,76,80,84,87,91,94,99,103,107,112,118,124

%N Number of partitions of n into pentagonal parts.

%H Seiichi Manyama, <a href="/A218379/b218379.txt">Table of n, a(n) for n = 0..10000</a> (terms 1..100 from Antonio Roldán)

%e A(15)=5 because 15 = 12+1+1+1 = 5+5+5 = 5+5+1+1+1+1+1 = 5+1+1+1+1+1+1+1+1+1+1 = 1+1+1+1+1+1+1+1+1+1+1+1+1+1+1 with 12, 5, 1 pentagonal numbers.

%o (PARI) {for (n=1, 100,p=truncate((1+sqrt(24*n+1))/6);m=polcoeff(prod(k=1,p,q=(3*k-1)*k/2;sum(h=0,truncate(n/q+1),x^(h*q))),n);write("B218379.txt",n," ",m))}

%Y Cf. A000326, A095699.

%K nonn

%O 0,6

%A _Antonio Roldán_, Oct 27 2012

%E a(0) = 1 prepended by _Seiichi Manyama_, Dec 09 2017

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 21 05:34 EDT 2024. Contains 372728 sequences. (Running on oeis4.)