A061888 Numbers k such that k^2 is the sum of the first m primes for some m.

10, 5063, 14573, 17098, 1916357, 468726713734

Offset

1,1

Links

Table of n, a(n) for n=1..6.

G. L. Honaker Jr. and C. Caldwell, Prime Curios!: 9

Carlos Rivera, Problem 9: Sum of first k primes is perfect square, The Prime Puzzles and Problems Connection.

Formula

a(n)^2 = A061890(n).

Example

10^2 = 2+3+5+7+11+13+17+19+23, so 10 is in the sequence.

Crossrefs

Cf. A033997, A033998, A061890.

Sequence in context: A223055 A308488 A180419 * A348082 A117803 A356041

Adjacent sequences: A061885 A061886 A061887 * A061889 A061890 A061891

Keyword

nonn,hard,more

Author

David W. Wilson, May 12 2001

Extensions

a(6) from Giovanni Resta, May 27 2003

Edited by Ray Chandler, Mar 20 2007

Status

approved