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 A135462 #13 Feb 28 2018 08:09:52 %S A135462 0,0,0,6,12,12,12,24,24,24,24,24,24,36,36,36,36,36,36,48,48,48,48,48, %T A135462 48,54,54,54,54,54,54,66,66,66,66,66,66,78,78,78,78,78,78,90,90,90,90, %U A135462 90,90,90,90,90,90,90,90,90,90,90,90,90,90,102,102,102,102,102 %N A135462 a(n) = number of Eisenstein primes (see A055664) of norm <= n. %D A135462 L. W. Reid, The Elements of the Theory of Algebraic Numbers, MacMillan, NY, 1910, see Chap. VI. %F A135462 a(n) = a(n-1) + A055667(n) for n > 0. - _Seiichi Manyama_, Dec 09 2017 %t A135462 A055667[n_] := Which[n == 3, 6, PrimeQ[n] && Mod[n, 6] == 1, 12, PrimeQ[p = Sqrt[n]] && Mod[p, 3] == 2, 6, True, 0]; Accumulate[Array[A055667, 66, 0]] (* _Jean-François Alcover_, Feb 28 2018 *) %Y A135462 Cf. A135461, A055664, A055667. %K A135462 nonn %O A135462 0,4 %A A135462 _N. J. A. Sloane_, Feb 06 2008 %E A135462 Terms corrected by _Seiichi Manyama_, Dec 09 2017