OFFSET
1,1
COMMENTS
31 is a prime number; 31+37+31*37 = 1215 = 3^5*5 is composite. The prime number 13 yields, when added to 31+37, the divisor 81. Therefore 31 is in the sequence.
MATHEMATICA
a = {}; For[n = 1, n < 200, n++, b = Prime[n] + Prime[n + 1] + Prime[n]*Prime[n + 1]; If[ ! PrimeQ[b], For[i = 1, Prime[i] < Prime[n]*Prime[n + 1], i++, If[Mod[ b, Prime[i] + Prime[n] + Prime[n + 1]] == 0, AppendTo[a, Prime[n]]]]]]; Union[a, a]
CROSSREFS
KEYWORD
nonn,less
AUTHOR
J. M. Bergot, Aug 15 2007
EXTENSIONS
Edited and extended by Stefan Steinerberger, Nov 22 2007
STATUS
approved