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A193350
Sum of even divisors of tau(n).
2
0, 2, 2, 0, 2, 6, 2, 6, 0, 6, 2, 8, 2, 6, 6, 0, 2, 8, 2, 8, 6, 6, 2, 14, 0, 6, 6, 8, 2, 14, 2, 8, 6, 6, 6, 0, 2, 6, 6, 14, 2, 14, 2, 8, 8, 6, 2, 12, 0, 8, 6, 8, 2, 14, 6, 14, 6, 6, 2, 24, 2, 6, 8, 0, 6, 14, 2, 8, 6, 14, 2, 24, 2, 6, 8, 8, 6, 14, 2, 12, 0, 6, 2, 24, 6, 6, 6, 14, 2, 24, 6, 8, 6, 6, 6, 24, 2, 8, 8, 0
OFFSET
1,2
LINKS
FORMULA
a(n) = A146076(A000005(n)). - Antti Karttunen, May 28 2017
EXAMPLE
a(24) = 14 because tau(24) = 8 and the sum of the 3 even divisors {2, 4, 8} is 14.
MATHEMATICA
Table[Total[Select[Divisors[DivisorSigma[0, n]], EvenQ[ # ]&]], {n, 74}]
PROG
(PARI) a(n)=sumdiv(sigma(n, 0), d, (1-d%2)*d);
CROSSREFS
Cf. A000290 (the positions of zeros).
Sequence in context: A094671 A354826 A202015 * A021458 A279741 A099064
KEYWORD
nonn
AUTHOR
Michel Lagneau, Jul 23 2011
EXTENSIONS
Data section extended to 100 terms by Antti Karttunen, May 28 2017
STATUS
approved