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A156190 Number of divisors d of n! such that d-1 is prime. 2
0, 0, 2, 6, 9, 18, 29, 43, 66, 101, 187, 257, 470, 717, 1033, 1293, 2442, 3168, 6011, 7911, 11179, 16888, 32603, 39587, 53063, 79742, 97707, 127679, 246428, 302205, 585129, 670409, 923535, 1385145, 1813935, 2099557, 4091926, 6142573, 8416157 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Ray Chandler, Table of n, a(n) for n=1..42

FORMULA

a(n) = A072627(A000142(n)).

MATHEMATICA

Table[Count[Divisors[n!], _?(PrimeQ[#-1]&)], {n, 40}] (* Harvey P. Dale, Feb 22 2020 *)

CROSSREFS

Cf. A072627, A067847.

Sequence in context: A002886 A028724 A222048 * A285446 A076738 A291100

Adjacent sequences: A156187 A156188 A156189 * A156191 A156192 A156193

KEYWORD

nonn

AUTHOR

Ray Chandler, Feb 05 2009

STATUS

approved

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Last modified February 3 23:01 EST 2023. Contains 360045 sequences. (Running on oeis4.)