A178156 Numbers m such that (m-1)! is not divisible by m^2.

2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 17, 19, 22, 23, 26, 29, 31, 34, 37, 38, 41, 43, 46, 47, 53, 58, 59, 61, 62, 67, 71, 73, 74, 79, 82, 83, 86, 89, 94, 97, 101, 103, 106, 107, 109, 113, 118, 122, 127, 131, 134, 137, 139, 142, 146, 149, 151, 157, 158, 163

Offset

1,1

Comments

Union of {8, 9} and A001751.

References

G. Pólya and G. Szegő, Problems and Theorems in Analysis II (Springer 1924, reprinted 1972), Part Eight, Chap. 3, Sect. 1, Problem 133b.

Links

Table of n, a(n) for n=1..62.

Mathematica

Select[Range[200], !Divisible[(#-1)!, #^2]&] (* Harvey P. Dale, Mar 06 2016 *)

Prog

(PARI) for(m=1, 3e2, if((m-1)!%m^2, print1(m", "))) \\ Charles R Greathouse IV, Aug 21 2011
(Haskell)
import Data.List (insert)
a178156 n = a178156_list !! (n-1)
a178156_list = insert 9 $ insert 8 a001751_list
-- Reinhard Zumkeller, Oct 14 2014

Crossrefs

Cf. A046022, A000142, A174460.

Cf. A001751.

Sequence in context: A362184 A368904 A229991 * A334294 A177054 A247760

Adjacent sequences: A178153 A178154 A178155 * A178157 A178158 A178159

Keyword

nonn

Author

Reinhard Zumkeller, Dec 17 2010

Extensions

Entries corrected by Charles R Greathouse IV, Aug 21 2011

Status

approved