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A328224 Numbers k such that each of k, k+1, k+2, and k+4 is a sum of two squares. 2
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 (list; graph; refs; listen; history; text; internal format)
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: A303145 A213349 A032444 * A017114 A092820 A060300

Adjacent sequences:  A328220 A328221 A328223 * A328225 A328226 A328227

KEYWORD

nonn

AUTHOR

Max Alekseyev, Oct 08 2019

STATUS

approved

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Last modified November 12 09:25 EST 2019. Contains 329054 sequences. (Running on oeis4.)