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A065244
Primes of form p = 2 + Sum_{k = 1..m} k^2 for some m.
1
3, 7, 821, 1787, 2111, 3313, 3797, 5527, 6203, 13687, 31397, 40427, 63367, 116797, 137827, 208337, 238967, 247067, 281297, 348553, 723907, 811037, 1048063, 1511017, 1538573, 1771177, 2268317, 3064987, 4298387, 4694923, 5239627
OFFSET
1,1
FORMULA
A000330(m)+2 gives primes.
EXAMPLE
821 = 2 + (1 + 4 + 9 + 16 + 25 + 36 + 49 + 64 + 81 + 100 + 121 + 144 + 169) = 2 + 919 = c + Sum[k^2;1...13]. Instead of c = 2 several other constants give numerous solutions.
CROSSREFS
Sequence in context: A302987 A092568 A055624 * A012844 A104052 A062625
KEYWORD
nonn
AUTHOR
Labos Elemer, Oct 24 2001
STATUS
approved