OFFSET
1,1
COMMENTS
See A039685 for further information about these numbers.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..400
Albert H. Beiler, Recreations in the Theory of Numbers (2d ed. 1966), p.139.
Index entries for linear recurrences with constant coefficients, signature (1,2,-2,-1,1).
FORMULA
a(n) = A039685(n)^2.
MATHEMATICA
Select[Table[n*10^3+444, {n, 50000}], IntegerQ[Sqrt[#]]&] (* Harvey P. Dale, Jun 19 2020 *)
Flatten[Table[500n+{38, -38}, {n, 0, 20}]]^2//Union (* Harvey P. Dale, Jan 26 2025 *)
PROG
(PARI) a039685(n) = 250*n+87*(-1)^n-125
a(n) = a039685(n)^2
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Felix Fröhlich, Oct 29 2019
STATUS
approved