OFFSET
1,1
COMMENTS
All terms are multiples of 144. - Zak Seidov, Nov 27 2013
LINKS
Donovan Johnson, 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
720 = 27^2 - 3^2 = 28^2 - 8^2 = 29^2 - 11^2.
MATHEMATICA
Select[Range[172*10^4], AllTrue[Sqrt[(Floor[Sqrt[#]]+{1, 2, 3})^2-#], IntegerQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 18 2021 *)
PROG
(PARI) sq3(n) = {for (i=1, n, a = sqrtint(i) + 1; if (issquare(a^2-i) && issquare((a+1)^2-i) && issquare((a+2)^2-i), print1(i, ", ")); ); }
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Oct 30 2012
STATUS
approved