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 A151784 #17 Nov 17 2022 05:27:10 %S A151784 1,1,6,1,6,6,36,1,6,6,36,6,36,36,216,1,6,6,36,6,36,36,216,6,36,36,216, %T A151784 36,216,216,1296,1,6,6,36,6,36,36,216,6,36,36,216,36,216,216,1296,6, %U A151784 36,36,216,36,216,216,1296,36,216,216,1296,216,1296,1296,7776,1,6,6,36,6,36,36 %N A151784 a(n) = 6^(wt(n) - 1) where wt(n) = A000120(n). %e A151784 From _Omar E. Pol_, Jul 21 2009: (Start) %e A151784 If written as a triangle: %e A151784 1; %e A151784 1,6; %e A151784 1,6,6,36; %e A151784 1,6,6,36,6,36,36,216; %e A151784 1,6,6,36,6,36,36,216,6,36,36,216,36,216,216,1296; %e A151784 1,6,6,36,6,36,36,216,6,36,36,216,36,216,216,1296,6,36,36,216,36,216,216,... %e A151784 (End) %o A151784 (Python 3.10+) %o A151784 def A151784(n): return 6**(n.bit_count()-1) # _Chai Wah Wu_, Nov 15 2022 %o A151784 (PARI) a(n) = 6^(hammingweight(n)-1); \\ _Michel Marcus_, Nov 15 2022 %Y A151784 Cf. A000120, A048881, A048896, A147610, A151780, A151783, A000120. %Y A151784 Cf. A000400. - _Omar E. Pol_, Jul 21 2009 %K A151784 nonn %O A151784 1,3 %A A151784 _N. J. A. Sloane_, Jun 25 2009