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A064649 Row sums of the table A047916. 4
1, 4, 12, 40, 140, 816, 5082, 40800, 363258, 3632880, 39916910, 479052528, 6227020956, 87178936992, 1307674429440, 20922800222848, 355687428096272, 6402373892575992, 121645100408832342, 2432902011892837920 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harry J. Smith, Table of n, a(n) for n=1..100

FORMULA

a(n) = Sum_{d|n} phi(n/d)*(n/d)^d*d!. - Michel Marcus, Mar 06 2016

MAPLE

A064649 := proc(n) local d, s; s := 0; for d in divisors(n) do s := s + phi(n/d)*(n/d)^d*d!; od; RETURN(s); end;

MATHEMATICA

a[n_] := DivisorSum[n, EulerPhi[n/#]*(n/#)^#*#!&]; Array[a, 20] (* Jean-Fran├žois Alcover, Mar 06 2016 *)

PROG

(PARI) { for (n=1, 100, a=0; v=divisors(n); for (i=1, length(v), d=v[i]; a+=eulerphi(n/d)*(n/d)^d*d!); write("b064649.txt", n, " ", a) ) } \\ Harry J. Smith, Sep 21 2009

(PARI) a(n) = sumdiv(n, d, eulerphi(n/d)*(n/d)^d*d!); \\ Michel Marcus, Mar 06 2016

(Haskell)

a064649 = sum . a047916_row  -- Reinhard Zumkeller, Mar 19 2014

CROSSREFS

Also n*A061417[n]. Cf. A047918, A002619.

Sequence in context: A221652 A259806 A100320 * A149332 A149333 A074032

Adjacent sequences:  A064646 A064647 A064648 * A064650 A064651 A064652

KEYWORD

nonn

AUTHOR

Antti Karttunen, Oct 04 2001

STATUS

approved

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Last modified May 27 16:48 EDT 2022. Contains 354110 sequences. (Running on oeis4.)