A249072 - OEIS

A249072

Sum of prime indices in the prime factorization of A249337(n), counted with multiplicity: a(n) = A056239(A249337(n)).

0, 1, 0, 1, 1, 2, 0, 2, 1, 2, 2, 2, 3, 0, 2, 3, 1, 3, 2, 4, 0, 3, 2, 3, 3, 3, 4, 1, 3, 3, 4, 2, 4, 2, 4, 3, 4, 3, 5, 0, 3, 4, 4, 3, 6, 0, 4, 4, 4, 5, 1, 4, 4, 6, 1, 3, 5, 2, 5, 2, 4, 5, 3, 5, 3, 4, 5, 4, 4, 7, 0, 3, 7, 1, 4, 5, 3, 5, 4, 8, 0, 4, 5, 4, 6, 2, 6, 2, 5, 5, 4, 6, 3, 8, 1, 4, 9, 0

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OFFSET

1,6

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..12580

FORMULA

a(n) = A056239(A249337(n)).

PROG

(PARI)

A049084(n) = if(isprime(n), primepi(n), 0); \\ This function from Charles R Greathouse IV

A056239(n) = { my(f); if(1==n, 0, f=factor(n); sum(i=1, #f~, f[i, 2] * A049084(f[i, 1]))); }

A249072_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("b249072_upto12580.txt", n, " ", a_n); counts[1+a_n]++; if(1 == n, a_k = 2, a_k = counts[1+a_n])); };

A249072_write_bfile(12580);

(Scheme) (define (A249072 n) (A056239 (A249337 n)))

CROSSREFS

Cf. A056239, A249337, A249338.

Cf. A249341 (positions of zeros), A249342 (positions of records).

Sequence in context: A219791 A029345 A153149 * A174007 A330709 A045450

Adjacent sequences: A249069 A249070 A249071 * A249073 A249074 A249075

KEYWORD

nonn

AUTHOR

Antti Karttunen, Oct 26 2014

STATUS

approved