This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A332574 #7 Feb 17 2020 09:45:33 %S A332574 127,631,751,1327,1527,1687,1711,2031,2047,2487,2647,3207,3271,3351, %T A332574 3511,3831,4567,4791,4911,5127,6007,6087,6711,7431,8247,8367,8391, %U A332574 8407,8551,8751,8871,9031,9447,9991,10407,10551,10887,10927,11631,12471,12567,12631,13807 %N A332574 Numbers k such that k, k + 1 and k + 2 are all norm-deficient in Gaussian integers (A332572). %H A332574 Amiram Eldar, <a href="/A332574/b332574.txt">Table of n, a(n) for n = 1..10000</a> %e A332574 127 is a term since 127, 128 and 129 are all norm-deficient in Gaussian integers (A332572). %t A332574 normDefQ[z_] := Abs[DivisorSigma[1, z, GaussianIntegers -> True]]^2 < 2*Abs[z]^2; Select[Range[10^4], AllTrue[# + Range[0, 2], normDefQ] &] %Y A332574 Cf. A005100, A103228, A103229, A103230, A317047, A332572, A332573. %K A332574 nonn %O A332574 1,1 %A A332574 _Amiram Eldar_, Feb 16 2020