cp's OEIS Frontend

A316436 Sum divided by GCD of the integer partition with Heinz number n > 1.

%I A316436 #13 Sep 15 2018 15:54:57
%S A316436 1,1,2,1,3,1,3,2,4,1,4,1,5,5,4,1,5,1,5,3,6,1,5,2,7,3,6,1,6,1,5,7,8,7,
%T A316436 6,1,9,4,6,1,7,1,7,7,10,1,6,2,7,9,8,1,7,8,7,5,11,1,7,1,12,4,6,3,8,1,9,
%U A316436 11,8,1,7,1,13,8,10,9,9,1,7,4,14,1,8,10,15,6,8,1,8,5,11,13,16,11,7,1,9,9,8,1,10,1,9,9
%N A316436 Sum divided by GCD of the integer partition with Heinz number n > 1.
%C A316436 The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).
%H A316436 Antti Karttunen, <a href="/A316436/b316436.txt">Table of n, a(n) for n = 2..65537</a>
%H A316436 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>
%H A316436 <a href="/index/He#Heinz">Index entries for sequences related to Heinz numbers</a>
%p A316436 a:= n-> (l-> add(i, i=l)/igcd(l[]))(map(i->
%p A316436       numtheory[pi](i[1])$i[2], ifactors(n)[2])):
%p A316436 seq(a(n), n=2..100);  # _Alois P. Heinz_, Jul 03 2018
%t A316436 Table[With[{pms=If[n===1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]]},Total[pms]/GCD@@pms],{n,2,100}]
%o A316436 (PARI) A316436(n) = { my(f = factor(n), pis = apply(p -> primepi(p), f[, 1]~), es = f[, 2]~, g = gcd(pis)); sum(i=1, #f~, pis[i]*es[i])/g; }; \\ _Antti Karttunen_, Sep 10 2018
%Y A316436 Cf. A056239, A289508, A289509, A290103, A290104, A296150, A316430, A316431, A316432, A316437.
%K A316436 nonn
%O A316436 2,3
%A A316436 _Gus Wiseman_, Jul 03 2018
%E A316436 More terms from _Antti Karttunen_, Sep 10 2018