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 A066281 #12 Sep 18 2024 16:34:26 %S A066281 0,0,0,0,0,3,5,11,11,24,35,84,92,174,254,606,658,1255,1769,4353,4667, %T A066281 9131 %N A066281 Number of 3-dimensional polyominoes (or polycubes) with n cells and rotational symmetry group of order exactly 4. %C A066281 The sequence counts "one-sided" polycubes (A000162); chiral polycubes count twice. - _John Mason_, Sep 18 2024 %D A066281 W. F. Lunnon, Symmetry of cubical and general polyominoes, pp. 101-108 of R. C. Read, editor, Graph Theory and Computing. Academic Press, NY, 1972. %F A066281 a(n) = 2*A(n)+2*BB(n)+2*BC(n)+AE(n)+BFF(n)+CJ(n)+EEE(n)+EF(n)+EFF(n), see Lunnon paper for naming convention. - _John Mason_, Sep 18 2024 %Y A066281 See A000162, A066273, A066283, A066287, A066288, A066453, A066454. %K A066281 nonn,more %O A066281 1,6 %A A066281 Brendan Owen (brendan_owen(AT)yahoo.com), Jan 01 2002 %E A066281 Name clarified and more terms from _John Mason_, Sep 18 2024