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A131693
Numbers n such that S(n) = 0, where S(n) = (S(n-1) + A000040(n+1))*(-1)^n; S(0)=0, n >= 1.
0
10, 14, 18, 4290, 4392, 4434, 4440, 4456, 4480, 48596, 48620, 48744, 49540, 49544, 49722, 55058, 55078, 55200, 56466, 56474, 60110, 60128, 60462, 60750, 61328, 61486, 62114, 62758, 62770, 62974, 62992, 63022, 63076, 63094, 63272, 63802
OFFSET
1,1
COMMENTS
Or, with A065091(odd primes), numbers n such that S(n) = 0, where S(n) = (S(n-1) + A065091(n))*(-1)^n; S(0)=0, n >= 1.
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