# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a056898 Showing 1-1 of 1 %I A056898 #10 Mar 04 2018 10:34:52 %S A056898 1,0,0,1,0,1,0,3,2,1,0,1,0,3,2,1,0,1,0,3,4,1,0,7,2,9,2,1,0,1,0,3,2,3, %T A056898 6,1,0,3,2,1,0,1,0,3,4,1,0,5,2,3,4,1,0,5,2,9,2,1,0,1,0,3,2,3,6,1,0,9, %U A056898 2,1,0,1,0,3,2,5,6,1,0,3,4,1,0,5,2,9,4,1,0,7,4,3,2,3,6,1,0,3,2 %N A056898 a(n) = smallest number m such that m^2+n is prime. %H A056898 Antti Karttunen, Table of n, a(n) for n = 1..65537 %F A056898 a(n) = sqrt(A056896(n)-n) = sqrt(A056897(n)). %F A056898 For p a prime: a(p) = 0 (and a(p-1) = 1 if p<>3). %e A056898 a(8) = 3 since 3^2+8 = 17 which is prime. %o A056898 (PARI) A056898(n) = { my(m=0); while(!isprime((m*m)+n),m++); (m); }; \\ _Antti Karttunen_, Mar 04 2018 %Y A056898 Cf. A000040, A002496, A056892, A056893, A056894, A056895, A056896, A056897. %K A056898 nonn %O A056898 1,8 %A A056898 _Henry Bottomley_, Jul 05 2000 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE