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 A187141 #15 Aug 06 2014 16:23:20 %S A187141 2,1,4,6,2,2,2,2,6,6,2,12,14,3,4,4,4,3,2,2,4,3,2,4,4,3,8,6,2,12,10,2, %T A187141 4,2,2,18,10,2,28,34,5,6,7,7,6,2,2,8,7,5,8,8,6,4,2,2,4,2,2,4,2,2,6,2, %U A187141 2,6,5,2,4,5,2,6,2,2,8,7,2,6,6,6,10,6,2,12,10,2,4,2,2,18,14,3,20,18,2,4,2,2,6,4,4,4,2,2,4,2,2,24,10,2,20,26,4,4,4,4,42,18,2,68 %N A187141 Number of lunar divisors of n in base 3. %H A187141 D. Applegate, M. LeBrun and N. J. A. Sloane, <a href="http://arxiv.org/abs/1107.1130">Dismal Arithmetic</a> [Note: we have now changed the name from "dismal arithmetic" to "lunar arithmetic" - the old name was too depressing] %H A187141 <a href="/index/Di#dismal">Index entries for sequences related to dismal (or lunar) arithmetic</a> %e A187141 If written as a triangle, with rows of length 2*3^i: %e A187141 2, 1, %e A187141 4, 6, 2, 2, 2, 2, %e A187141 6, 6, 2, 12, 14, 3, 4, 4, 4, 3, 2, 2, 4, 3, 2, 4, 4, 3, %e A187141 8, 6, 2, 12, 10, 2, 4, 2, 2, 18, 10, 2, 28, 34, 5, 6, 7, 7, 6, 2, 2, 8, 7, 5, 8, 8, 6, 4, 2, 2, 4, 2, 2, 4, 2, 2, 6, 2, 2, 6, 5, 2, 4, 5, 2, 6, 2, 2, 8, 7, 2, 6, 6, 6, %e A187141 10, 6, 2, 12, 10, 2, 4, 2, 2, 18, 14, 3, 20, 18, 2, 4, 2, 2, 6, 4, 4, 4, 2, 2, 4, 2, 2, 24, 10, 2, 20, 26, 4, 4, 4, 4, 42, 18, 2, 6, ... %Y A187141 Cf. A007089. This is the base-3 analog of A067399. %K A187141 base,nonn %O A187141 1,1 %A A187141 _N. J. A. Sloane_, Mar 05 2011