A332573 Numbers k such that k and k + 1 are both norm-deficient in Gaussian integers (A332572).

7, 16, 127, 128, 151, 248, 256, 343, 472, 536, 568, 631, 632, 751, 752, 823, 856, 943, 1048, 1111, 1136, 1207, 1303, 1327, 1328, 1336, 1432, 1527, 1528, 1591, 1687, 1688, 1711, 1712, 1783, 1816, 1912, 2031, 2032, 2047, 2048, 2103, 2167, 2263, 2416, 2487, 2488

Offset: 1

Author

Amiram Eldar, Feb 16 2020

Keywords

• nonn

Examples

			7 is a term since both 7 and 7 + 1 = 8 are norm-deficient in Gaussian integers (A332572).
		

Links

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

Crossrefs

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

Programs

Mathematica

normDefQ[z_] := Abs[DivisorSigma[1, z, GaussianIntegers -> True]]^2 < 2*Abs[z]^2; Select[Range[2500], normDefQ[#] && normDefQ[# + 1] &]