cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A002221 a(n) is the number of partitions of 4n that can be obtained by adding together four (not necessarily distinct) partitions of n.

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%I A002221 M3861 N1583 #26 May 24 2016 05:28:48
%S A002221 1,5,15,55,140,448,1022,2710,6048,14114,28831,64091,123649,251295,
%T A002221 476835,916972,1654044,3080159,5377431,9624588,16490017,28433473,
%U A002221 47423409,80279375
%N A002221 a(n) is the number of partitions of 4n that can be obtained by adding together four (not necessarily distinct) partitions of n.
%D A002221 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A002221 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A002221 N. Metropolis and P. R. Stein, <a href="http://dx.doi.org/10.1016/S0021-9800(70)80091-6">An elementary solution to a problem in restricted partitions</a>, J. Combin. Theory, 9 (1970), 365-376.
%Y A002221 See A002219 for further details. Cf. A002220, A002222, A213074.
%Y A002221 A column of A213086.
%K A002221 nonn,more
%O A002221 1,2
%A A002221 _N. J. A. Sloane_
%E A002221 Edited by _N. J. A. Sloane_, Jun 03 2012
%E A002221 a(12)-a(16) from _Alois P. Heinz_, Jul 10 2012
%E A002221 a(17)-a(24) from _Sean A. Irvine_, Sep 05 2013