A218486 Positive numbers differing from next 2 greater squares by squares.

48, 96, 160, 240, 288, 336, 448, 480, 576, 720, 960, 1008, 1344, 1440, 1728, 2016, 2160, 2400, 2640, 2688, 3168, 3360, 3456, 3744, 4320, 4368, 4480, 5040, 5280, 5760, 6336, 6720, 7200, 7488, 8640, 8736, 8800, 9408, 10080, 10560, 10800, 11520, 12096, 12480

Offset

1,1

Comments

All terms are even. The sequence is infinite. E.g., positive terms of A173121 {48, 288, 960, 2400, 5040, 9408, 16128, 25920, 39600,...} is infinite subsequence of A218486. - Zak Seidov, Nov 26 2013

Another infinite subsequence is {96, 480, 1440, 3360, 6720, 12096, 20160, ...} = 96 *binomial(m,4) = 96*(positive terms in A000332). - Zak Seidov, Nov 26 2013

Links

Zak Seidov, Table of n, a(n) for n = 1..1000

E. J. Barbeau, Numbers differing from consecutive squares by squares, Canad. Math. Bull. 28(1985), pp. 337-342.

Example

48 = 7^2 - 1^2 = 8^2 - 4^2.

Prog

(PARI) sq2(n) = {for (i=1, n, a = sqrtint(i) + 1; if (issquare(a^2-i) && issquare((a+1)^2-i), print1(i, ", ")); ); }

Crossrefs

Cf. A173121, A218485, A218487, A218488.

Sequence in context: A260063 A211723 A274899 * A043418 A031486 A044186

Adjacent sequences: A218483 A218484 A218485 * A218487 A218488 A218489

Keyword

nonn

Author

Michel Marcus, Oct 30 2012

Status

approved