A064649 Row sums of the table A047916.

1, 4, 12, 40, 140, 816, 5082, 40800, 363258, 3632880, 39916910, 479052528, 6227020956, 87178936992, 1307674429440, 20922800222848, 355687428096272, 6402373892575992, 121645100408832342, 2432902011892837920

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-François 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