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A229342 a(n) = sigma(n'), the sum of divisors of the arithmetic derivative of n. 6
1, 1, 7, 1, 6, 1, 28, 12, 8, 1, 31, 1, 13, 15, 63, 1, 32, 1, 60, 18, 14, 1, 84, 18, 24, 40, 63, 1, 32, 1, 186, 24, 20, 28, 168, 1, 32, 31, 126, 1, 42, 1, 124, 56, 31, 1, 248, 24, 78, 42, 120, 1, 121, 31, 168, 36, 32, 1, 168, 1, 48, 72, 508, 39, 62, 1, 195, 42 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,3

COMMENTS

a(1) is undefined.

LINKS

Antti Karttunen, Table of n, a(n) for n = 2..20000

FORMULA

a(n) = A000203(A003415(n)).

EXAMPLE

For n=4, sigma(n') = sigma(4') = sigma(4) = 7.

For n=7, sigma(n') = sigma(7') = sigma(1) = 1.

PROG

(PARI) rd(n) = {local(fac); if(n<1, 0, fac=factor(n); sum(i=1, matsize(fac)[1], n*fac[i, 2]/fac[i, 1]; )); } \\ from A003415

a(n) = sigma(rd(n)); \\ Michel Marcus, Sep 24 2013

CROSSREFS

Cf. A000203, A003415.

Cf. also A229340, A229341, A229343, A229344.

Sequence in context: A154932 A026497 A010146 * A176438 A092615 A199279

Adjacent sequences:  A229339 A229340 A229341 * A229343 A229344 A229345

KEYWORD

nonn

AUTHOR

Luca Brigada Villa, Sep 24 2013

STATUS

approved

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Last modified January 23 03:15 EST 2022. Contains 350504 sequences. (Running on oeis4.)