A328224 Numbers k such that each of k, k+1, k+2, and k+4 is a sum of two squares.

0, 16, 144, 288, 576, 1152, 1600, 2304, 3328, 3600, 4624, 5184, 7056, 8352, 10368, 10656, 10816, 11808, 12112, 12240, 12544, 13120, 13840, 16704, 17424, 19600, 19728, 20736, 20752, 21312, 21904, 22048, 23200, 24480, 24784, 25920, 27792, 28960, 29520, 29824, 30976, 31264, 32400

Offset

1,2

Comments

All terms are divisible by 16. - Robert Israel, Oct 10 2019

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

ss:=  proc(n) option remember;
  andmap(t -> t[2]::even or t[1] mod 4 <> 3, ifactors(n)[2])
end proc:
select(k -> ss(k) and ss(k+1) and ss(k+2) and ss(k+4), 16*[$0..10^4]); # Robert Israel, Oct 10 2019

Mathematica

ok[n_] := AllTrue[{0, 1, 2, 4}, SquaresR[2, #+n] > 0 &]; Select[ Range[0, 32400], ok] (* Giovanni Resta, Oct 08 2019 *)

Prog

(Magma) [k:k in [0..33000]| forall{k+a: a in [0, 1, 2, 4]|NormEquation(1, k+a) eq true}]; // Marius A. Burtea, Oct 08 2019

Crossrefs

Cf. A001481, A140612, A304441.

Intersection of A082982 and A328223.

Sequence in context: A032444 A358263 A358262 * A017114 A331741 A092820

Adjacent sequences: A328221 A328222 A328223 * A328225 A328226 A328227

Keyword

nonn

Author

Max Alekseyev, Oct 08 2019

Status

approved