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.

A325510 Number of non-isomorphic multiset partitions of the multiset of prime indices of n!.

This page as a plain text file.
%I A325510 #9 Jan 17 2023 21:24:34
%S A325510 1,1,1,2,7,16,98,269,1397,7582,70520,259906,1677259,5229112,44726100,
%T A325510 666355170,4917007185,18459879921
%N A325510 Number of non-isomorphic multiset partitions of the multiset of prime indices of n!.
%F A325510 a(n) = A317791(n!).
%F A325510 a(n) = A318285(A181819(n!)) =  A318285(A325508(n)). - _Andrew Howroyd_, Jan 17 2023
%e A325510 Non-isomorphic representatives of the a(2) = 1 through a(5) = 16 multiset partitions:
%e A325510   {{1}}  {{12}}    {{1222}}        {{12333}}
%e A325510          {{1}{2}}  {{1}{222}}      {{1}{2333}}
%e A325510                    {{12}{22}}      {{12}{333}}
%e A325510                    {{2}{122}}      {{13}{233}}
%e A325510                    {{1}{2}{22}}    {{3}{1233}}
%e A325510                    {{2}{2}{12}}    {{33}{123}}
%e A325510                    {{1}{2}{2}{2}}  {{1}{2}{333}}
%e A325510                                    {{1}{23}{33}}
%e A325510                                    {{1}{3}{233}}
%e A325510                                    {{3}{12}{33}}
%e A325510                                    {{3}{13}{23}}
%e A325510                                    {{3}{3}{123}}
%e A325510                                    {{1}{1}{1}{23}}
%e A325510                                    {{1}{2}{3}{33}}
%e A325510                                    {{1}{3}{3}{23}}
%e A325510                                    {{1}{2}{3}{3}{3}}
%o A325510 (PARI) \\ Requires C(sig) from A318285.
%o A325510 a(n)={if(n<2, 1, my(f=factor(n!)[,2], sig=vector(vecmax(f))); for(i=1, #f, sig[f[i]]++); C(sig))} \\ _Andrew Howroyd_, Jan 17 2023
%Y A325510 Cf. A000142, A001055, A007716, A011371, A022559, A076716, A115627, A317791, A318285, A322583, A325272, A325276, A325508, A325509, A325511.
%K A325510 nonn,more
%O A325510 0,4
%A A325510 _Gus Wiseman_, May 08 2019
%E A325510 a(9)-a(17) from _Andrew Howroyd_, Jan 17 2023