OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
a(4) = (8+9+10)-(7) =20.
MATHEMATICA
scsp[n_]:=Module[{prs=Select[n, PrimeQ]}, Total[Complement[n, prs]]-Total[ prs]]; With[{nn=50}, scsp/@TakeList[Range[(nn(nn+1))/2], Range[nn]]]/. (1->0) (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 01 2019 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Amarnath Murthy, May 17 2004
EXTENSIONS
More terms from Sean A. Irvine, Oct 13 2009
STATUS
approved