A132956 The smallest perfect square which is a sum of n consecutive primes.

36, 49, 36, 961, 3600, 169, 1444, 100, 138384, 11449, 2304, 9025, 484, 60025, 7056, 35721, 8836, 85849, 25600, 6889, 40000, 961, 1156, 58081, 7056, 1369, 32400, 426409, 60516, 1849, 7396, 15129, 77284, 5329, 19600, 3249, 39204, 96721, 32400

Offset: 2

Author

Enoch Haga, Sep 06 2007

Keywords

• easy
• nonn

Comments

The smallest of these n consecutive primes is A132955(n).

Examples

			a(2)=36, because 2+3=5 is not a perfect square, 3+5=8 is not, 5+7=12 is not, 7+11 is not.. but 17+19=36=6^2 is.
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 2..100

Crossrefs

Cf. A132955, A132957.

Programs

PARI

a(n) = {ip = 1; while (! issquare(v=sum(i=ip, ip+n-1, prime(i))), ip++); v;} \\ Michel Marcus, Jun 08 2014

Extensions

Definition simplified, offset set to 2 by R. J. Mathar, Oct 30 2009