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A328223
Numbers k such that both k and k+4 are sums of two squares.
1
0, 1, 4, 5, 9, 13, 16, 25, 32, 36, 37, 41, 45, 49, 61, 64, 68, 81, 85, 97, 100, 109, 113, 117, 121, 144, 145, 149, 153, 160, 169, 181, 193, 196, 208, 221, 225, 229, 241, 256, 257, 261, 265, 277, 288, 289, 292, 313, 320, 324, 333, 349, 356, 361, 365, 369, 373, 388, 397, 400
OFFSET
1,3
MATHEMATICA
ok[n_] := AllTrue[{0, 4}, SquaresR[2, # + n] > 0 &]; Select[Range[0, 400], ok] (* Giovanni Resta, Oct 08 2019 *)
PROG
(Magma) [k: k in [0..400] | NormEquation(1, k) eq true and NormEquation(1, k+4) eq true]; // Marius A. Burtea, Oct 08 2019
CROSSREFS
Subsequence of A001481. Contains A328224 as a subsequence.
Sequence in context: A331531 A363319 A363267 * A363282 A116045 A096818
KEYWORD
nonn
AUTHOR
Max Alekseyev, Oct 08 2019
STATUS
approved