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A081402 a(n) = A008475(n!). 2
0, 2, 5, 11, 16, 30, 37, 149, 221, 369, 380, 1310, 1323, 2389, 2975, 33695, 33712, 72312, 72331, 269439, 282855, 545109, 545132, 4254514, 4269514, 8463974, 9999248, 35167130, 35167159, 71972737, 71972768, 2152347552, 2161914700 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..33.

EXAMPLE

a(1) = 0 since 1! = 1 has no prime factor;

a(8) = 2^7 + 3^2 + 5 + 7 = 149 since 8! = 2^7*3^2*5*7.

MATHEMATICA

ffi[x_] := Flatten[FactorInteger[x]] lf[x_] := Length[FactorInteger[x]] ba[x_] := Table[Part[ffi[x], 2*w-1], {w, 1, lf[x]}] ep[x_] := Table[Part[ffi[x], 2*w], {w, 1, lf[x]}] supo[x_] := Apply[Plus, ba[x]^ep[x]] Table[supo[w], {w, 1, 25}]

PROG

(PARI) a(n) = my(f=factor(n!)); sum(k=1, #f~, f[k, 1]^f[k, 2]); \\ Michel Marcus, Jul 09 2018

CROSSREFS

Cf. A008475, A000142, A081403, A081404.

Sequence in context: A082083 A287558 A024917 * A281023 A118660 A009770

Adjacent sequences:  A081399 A081400 A081401 * A081403 A081404 A081405

KEYWORD

nonn

AUTHOR

Labos Elemer, Mar 31 2003

STATUS

approved

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Last modified March 29 03:09 EDT 2020. Contains 333104 sequences. (Running on oeis4.)