1,1

Table of n, a(n) for n=1..56.

34 is in the sequence because 34 + 33^2 = 1123 and 34 + 35^2 = 1259 are both prime.

L:=[]; for k from 1 to 1000 do if isprime(k+(k-1)^2) and isprime(k+(k+1)^2) then L:=[op(L), k] fi od;

Cf. A027861.

Sequence in context: A094093 A240077 A237997 * A027947 A067236 A070763

Adjacent sequences: A108806 A108807 A108808 * A108810 A108811 A108812

easy,nonn

Walter Kehowski, Jul 04 2005

approved