cp's OEIS Frontend

A249338 Sum of prime indices in the prime factorization of A249336(n), counted with multiplicity: a(n) = A056239(A249336(n)).

%I A249338 #13 Oct 26 2014 20:48:55
%S A249338 0,0,1,0,2,0,2,1,1,2,2,2,3,0,3,1,2,3,2,4,0,3,2,3,3,3,4,1,3,3,4,2,4,2,
%T A249338 4,3,4,3,5,0,4,4,3,4,4,4,5,1,3,6,0,3,5,2,5,2,4,4,6,1,4,5,3,5,3,4,5,4,
%U A249338 4,7,0,4,5,3,7,1,3,5,4,8,0,4,5,4,6,2,6,2,5,5,4,6,3,8,1,4,9,0
%N A249338 Sum of prime indices in the prime factorization of A249336(n), counted with multiplicity: a(n) = A056239(A249336(n)).
%H A249338 Antti Karttunen, <a href="/A249338/b249338.txt">Table of n, a(n) for n = 1..12580</a>
%F A249338 a(n) = A056239(A249336(n)).
%F A249338 Other identities. For all n >= 1:
%F A249338 a(A249339(n)) = 0.
%F A249338 a(A249340(n)) = n-1. [A249340 gives the positions of records (just before each zero) that are consecutive nonnegative integers, A001477.]
%o A249338 (PARI)
%o A249338 A049084(n) = if(isprime(n), primepi(n), 0); \\ This function from _Charles R Greathouse IV_
%o A249338 A056239(n) = { my(f); if(1==n, 0, f=factor(n); sum(i=1, #f~, f[i,2] * A049084(f[i,1]))); }
%o A249338 A249338_write_bfile(up_to_n) = { my(counts, n, a_k, a_n); counts = vector(up_to_n); a_k = 1; for(n = 1, up_to_n, a_n = A056239(a_k); write("b249338_upto12580.txt", n, " ", a_n); counts[1+a_n]++; a_k = counts[1+a_n]); };
%o A249338 A249338_write_bfile(12580);
%o A249338 (Scheme) (define (A249338 n) (A056239 (A249336 n)))
%Y A249338 Cf. A001477, A056239, A249336, A249339 (positions of zeros), A249340 (positions of records), A249072.
%K A249338 nonn
%O A249338 1,5
%A A249338 _Antti Karttunen_, Oct 26 2014