A196924 Smallest prime(k) such that prime(k+n) + prime(k) is a perfect square.

17, 5, 2, 3, 61, 7, 83, 2, 173, 29, 11, 43, 1019, 2, 89, 3, 83, 397, 11, 47, 2, 101, 3, 17, 131, 13, 167, 59, 7, 83, 5, 193, 73, 17, 233, 67, 179, 2, 29, 5, 167, 3, 83, 47, 17, 43, 2, 41, 293, 101, 5, 137, 53, 281, 773, 17, 857, 13, 41, 11, 383, 7, 439, 503

Offset

1,1

Links

Table of n, a(n) for n=1..64.

Example

a(5) = 61 is the smallest initial prime of a subset of 6 consecutive primes {61, 67, 71, 73, 79, 83} such that 83 + 61 = 144 = 12^2.

Maple

A196924:= proc(n)
for k from 1 do
if issqr(ithprime(k+n)+ithprime(k)) then
return ithprime(k);
end if;
end do:
end proc:
seq(A196924(n), n=1..80) ;

Crossrefs

Cf. A000040, A196874, A196815.

Sequence in context: A070718 A040277 A367356 * A109215 A254070 A297982

Adjacent sequences: A196921 A196922 A196923 * A196925 A196926 A196927

Keyword

nonn

Author

Michel Lagneau, Oct 07 2011

Status

approved