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A270816 For each primary pseudoperfect number n, this sequence gives the sum of (n/p + 1)/p for every prime divisor p of n. 1
1, 3, 17, 691, 17521, 824473683, 19579678305, 3161039281414579992004338982115 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..8.

FORMULA

a(k) = Sum_{prime p|n(k)} (n(k)/p + 1)/p, where n(k) = A054377(k).

EXAMPLE

Prime factors of 42 are 2, 3 and 7: (42/2 + 1)/2 + (42/3 + 1)/3 + (42/7 + 1)/7 = 11 + 5 + 1 = 17.

MAPLE

with(numtheory): P:=proc(q) local a, b, k, n, x;

x:=[2, 6, 42, 1806, 47058, 2214502422, 52495396602, 8490421583559688410706771261086];

for n from 1 to nops(x) do a:=ifactors(x[n])[2];

b:=add((x[n]/a[k][1]+1)/a[k][1], k=1..nops(a)); print(b);

od; end: P(10^4);

CROSSREFS

Cf. A054377, A270815.

Sequence in context: A049985 A126579 A309060 * A217957 A252730 A225728

Adjacent sequences:  A270813 A270814 A270815 * A270817 A270818 A270819

KEYWORD

nonn,more

AUTHOR

Paolo P. Lava, Mar 23 2016

STATUS

approved

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Last modified May 26 18:08 EDT 2020. Contains 334630 sequences. (Running on oeis4.)