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%I #10 Jun 13 2017 10:19:06
%S 8,15,20,21,26,29,36,45,48,59,68,69,75,78,98,99,108,111,113,120,129,
%T 134,138,140,143,161,168,185,188,189,210,213,215,216,218,224,230,231,
%U 234,251,255,260,266,273,278,279,281,290,294,299,306,308,314,320,329,356
%N Numbers k such that k^2 + k - 41 is prime.
%e If k=8, then k^2 + n - 41 = 31 (prime).
%e If k=99, then k^2 + n - 41 = 9859 (prime).
%p isA133157 := proc(n) isprime(n*(n+1)-41) ; end: for n from 1 to 400 do if isA133157(n) then printf("%d, ",n) ; fi ; od: # _R. J. Mathar_, Jan 08 2008
%t Select[Range[7, 400], PrimeQ[ #^2 + # - 41] &] (* _Stefan Steinerberger_, Dec 24 2007 *)
%o (PARI) is(n)=isprime(n^2+n-41) \\ _Charles R Greathouse IV_, Jun 13 2017
%Y Cf. A002837.
%K nonn,easy
%O 1,1
%A _Parthasarathy Nambi_, Dec 17 2007
%E More terms from _Stefan Steinerberger_, Dec 24 2007
%E More terms from _R. J. Mathar_, Jan 08 2008