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A323069
Number of divisors d of n such that A049820(d) > 1 and A049820(d) is also a divisor of n.
3
0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 2, 0, 0, 1, 1, 0, 2, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 3, 0, 1, 0, 0, 1, 4, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 4, 0, 0, 0, 0, 0, 2, 0, 1, 0, 0, 0, 4, 0, 0, 0, 1, 0, 1, 0, 0, 0, 2, 0, 5, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 2, 0, 0, 0, 1, 0, 4, 0, 0, 0, 0, 0, 4, 0, 0, 1, 0, 0, 1, 0, 1, 2
OFFSET
1,12
LINKS
FORMULA
Sum_{d|n} [A049820(d) > 1 and A049820(d)|n], where [ ] is the Iverson bracket.
a(n) <= A323068(n).
a(n) >= A322358(n).
PROG
(PARI) A323069(n) = sumdiv(n, d, my(t=(d-numdiv(d))); ((t>1)&&!(n%t)));
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 05 2019
STATUS
approved