OFFSET
1,5
COMMENTS
a(n) is odd iff n is even and n/2 is not prime.
Convolution of A005171 with itself. - R. J. Mathar, Sep 10 2021
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
5=1+4=2+3=3+2=4+1, hence a(5)=2;
6=1+5=2+4=3+3=4+2=5+1, hence a(6)=0.
MATHEMATICA
Table[With[{nn=m}, Total[Table[If[NoneTrue[{n, nn-n}, PrimeQ], 1, 0], {n, nn-1}]]], {m, 80}] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 15 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Oct 21 2002
STATUS
approved