A066295 Number of Abelian groups of order n minus the number of non-Abelian groups of order n.

1, 1, 1, 2, 1, 0, 1, 1, 2, 0, 1, -1, 1, 0, 1, -4, 1, -1, 1, -1, 0, 0, 1, -9, 2, 0, 1, 0, 1, -2, 1, -37, 1, 0, 1, -6, 1, 0, 0, -8, 1, -4, 1, 0, 2, 0, 1, -42, 2, -1, 1, -1, 1, -9, 0, -7, 0, 0, 1, -9, 1, 0, 0, -245, 1, -2, 1, -1, 1, -2, 1, -38, 1, 0, 1, 0, 1, -4, 1, -42, -5, 0, 1, -11, 1, 0, 1, -6, 1, -6, 1, 0, 0

Offset: 1

Author

Sharon Sela (sharonsela(AT)hotmail.com), Jan 01 2002

Keywords

• sign

Links

• T. D. Noe, Table of n, a(n) for n = 1..2015 [a(1024) corrected by Andrey Zabolotskiy]

Crossrefs

Cf. A000688, A060689, A000001.

Programs

Mathematica

a[n_] := 2 FiniteAbelianGroupCount[n] - FiniteGroupCount[n];
a /@ Range[100] (* Jean-François Alcover, Jan 01 2020 *)

Formula

a(n) = A000688(n) - A060689(n).

Extensions

Edited by Dean Hickerson, Mar 04 2002

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 05 2003