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!)
A246231 Number of compositions of n into exactly four different parts with distinct multiplicities. 2
12600, 78120, 189000, 549000, 1389960, 2858640, 6471699, 15289662, 29639082, 64025820, 134997382, 267550925, 545274648, 1161661901, 2223888268, 4552401195, 9185643748, 17829746962, 35102264675, 71613947350, 135793314152, 270167493481, 534784841445 (list; graph; refs; listen; history; text; internal format)
OFFSET

20,1

LINKS

Alois P. Heinz and Vaclav Kotesovec, Table of n, a(n) for n = 20..220 (first 120 terms from Alois P. Heinz)

MATHEMATICA

b[n_, i_, s_List] := b[n, i, s] = If[n == 0, Total[s]!, If[i<1, 0, Expand[ Sum[ If[j>0 && MemberQ[s, j], 0, If[j == 0, 1, x]*b[n-i*j, i-1, If[j == 0, s, s ~Union~ {j}]]/j!], {j, 0, n/i}]]]]; a[n_] := Coefficient[b[n, n, {}], x, 4]; Table[a[n], {n, 20, 50}] (* Jean-Fran├žois Alcover, Feb 11 2015, after Alois P. Heinz *)

CROSSREFS

Column k=4 of A242896.

Sequence in context: A237086 A190109 A272516 * A248709 A261860 A187136

Adjacent sequences:  A246228 A246229 A246230 * A246232 A246233 A246234

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Aug 19 2014

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 August 12 17:17 EDT 2020. Contains 336439 sequences. (Running on oeis4.)