OFFSET
1,1
COMMENTS
EXAMPLE
S(9) = (..((0+3)*-1)+5)*1)+7)*-1)+11)*1)+13)*-1)+17)*1)+19)*-1)+23)*1)+29)*-1 = -31, S(10)=(-31 + 31)*1 = 0, hence 10 is a term.
S(13) = (..((0+3)*-1)+5)*1)+7)*-1)+11)*1)+13)*-1)+17)*1)+19)*-1)+23)*1)+29)*-1)+31)*1)+37)*-1)+41)*1)+43)*-1 = -47, S(14)=(-47 + 47)*1 = 0, hence 14 is a term.
MATHEMATICA
S=0; a=0; Do[S=(S+Prime[n+1])*(-1)^n; If[S==0, a++; Print[a, " ", n]], {n, 1, 10^8, 1}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Manuel Valdivia, Oct 03 2007
STATUS
approved