A268496 Indices of records in A268630 (= a(n)^2+a(n+1) is prime).

0, 1, 3, 5, 7, 9, 15, 16, 17, 23, 24, 29, 40, 49, 52, 63, 72, 73, 74, 77, 83, 89, 92, 93, 105, 110, 130, 145, 154, 161, 162, 165, 175, 182, 184, 189, 190, 198, 205, 213, 217, 218, 219, 222, 237, 239, 247, 251, 253, 255, 278, 293, 308, 311, 313, 331, 336, 339, 346, 351, 353, 362, 366

Offset: 0

Author

M. F. Hasler, Feb 09 2016

Keywords

• nonn

Comments

See A268497 for the actual record values.

Programs

PARI

show(n, f="/tmp/b268496.txt", c=0, a=0, u=[a-1])={for(n=1, n, a>=u[#u]&&if(f, write(f, c++-1, " "n-1), print1(n-1", ")); u=setunion(u, [a]); while(#u>1&&u[2]==u[1]+1, u=u[^1]); for(k=u[1]+1, 9e9, !setsearch(u, k) && isprime(a*a+k) && (a=k) && break))}