OFFSET
1,4
LINKS
T. D. Noe, Table of n, a(n) for n = 1..2015 [a(1024) corrected by Andrey Zabolotskiy]
MATHEMATICA
a[n_] := 2 FiniteAbelianGroupCount[n] - FiniteGroupCount[n];
a /@ Range[100] (* Jean-François Alcover, Jan 01 2020 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Sharon Sela (sharonsela(AT)hotmail.com), Jan 01 2002
EXTENSIONS
Edited by Dean Hickerson, Mar 04 2002
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 05 2003
STATUS
approved