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Revision History for A163371

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A163371

a(n) = tau(phi(sigma(n)))
(history; published version)

#12 by Bruno Berselli at Wed Dec 21 02:42:23 EST 2016

STATUS

reviewed

approved

#11 by Joerg Arndt at Wed Dec 21 02:25:07 EST 2016

STATUS

proposed

reviewed

#10 by Wesley Ivan Hurt at Mon Dec 19 20:52:46 EST 2016

STATUS

editing

proposed

#9 by Wesley Ivan Hurt at Mon Dec 19 20:52:30 EST 2016

DATA

1, 2, 2, 4, 2, 3, 3, 4, 6, 4, 3, 6, 4, 4, 4, 8, 4, 8, 4, 6, 5, 6, 4, 5, 8, 6, 5, 8, 4, 8, 5, 9, 5, 6, 5, 12, 6, 5, 8, 8, 6, 6, 6, 8, 8, 8, 5, 12, 9, 12, 8, 8, 6, 6, 8, 6, 6, 8, 5, 10, 8, 6, 10, 12, 8, 10, 6, 9, 6, 10, 8, 12, 9, 9, 12, 10, 6, 10, 6, 12, 8, 9, 8, 12, 9, 8, 6, 10, 8, 12

#8 by Wesley Ivan Hurt at Mon Dec 19 20:51:45 EST 2016

NAME

a(n) = tau(phi(sigma(n)))

COMMENTS

a(n) = A000005(A000010(A000203(n))) = A000005(A062401(n)) = A062821(A000203(n)).

FORMULA

a(n) = A000005(A000010(A000203(n))) = A000005(A062401(n)) = A062821(A000203(n)).

MAPLE

with(numtheory): A163371:=n->tau(phi(sigma(n))): seq(A163371(n), n=1..150); # Wesley Ivan Hurt, Dec 19 2016

CROSSREFS

Cf. A000005, A000010, A000203, A062401, A062821.

KEYWORD

nonn,easy,changed

STATUS

proposed

editing

#7 by G. C. Greubel at Mon Dec 19 19:38:04 EST 2016

STATUS

editing

proposed

#6 by G. C. Greubel at Mon Dec 19 19:38:00 EST 2016

PROG

(PARI) vector(50, n, numdiv(eulerphi(sigma(n)))) \\ G. C. Greubel, Dec 19 2016

STATUS

proposed

editing

#5 by G. C. Greubel at Mon Dec 19 19:24:35 EST 2016

STATUS

editing

proposed

#4 by G. C. Greubel at Mon Dec 19 19:24:27 EST 2016

DATA

#3 by G. C. Greubel at Mon Dec 19 19:22:02 EST 2016

LINKS

G. C. Greubel, <a href="/A163371/b163371.txt">Table of n, a(n) for n = 1..1000</a>

MATHEMATICA

DivisorSigma[0, EulerPhi[DivisorSigma[1, Range[100]]]] (* G. C. Greubel, Dec 19 2016 *)

STATUS

approved

editing