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A332574 Numbers k such that k, k + 1 and k + 2 are all norm-deficient in Gaussian integers (A332572). 1
127, 631, 751, 1327, 1527, 1687, 1711, 2031, 2047, 2487, 2647, 3207, 3271, 3351, 3511, 3831, 4567, 4791, 4911, 5127, 6007, 6087, 6711, 7431, 8247, 8367, 8391, 8407, 8551, 8751, 8871, 9031, 9447, 9991, 10407, 10551, 10887, 10927, 11631, 12471, 12567, 12631, 13807 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

EXAMPLE

127 is a term since 127, 128 and 129 are all norm-deficient in Gaussian integers (A332572).

MATHEMATICA

normDefQ[z_] := Abs[DivisorSigma[1, z, GaussianIntegers -> True]]^2 < 2*Abs[z]^2; Select[Range[10^4], AllTrue[# + Range[0, 2], normDefQ] &]

CROSSREFS

Cf. A005100, A103228, A103229, A103230, A317047, A332572, A332573.

Sequence in context: A152783 A299890 A200813 * A049202 A204737 A060201

Adjacent sequences:  A332571 A332572 A332573 * A332575 A332576 A332577

KEYWORD

nonn

AUTHOR

Amiram Eldar, Feb 16 2020

STATUS

approved

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Last modified December 4 02:40 EST 2021. Contains 349469 sequences. (Running on oeis4.)