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 A014257 #10 Jul 08 2025 05:34:55 %S A014257 1,2,4,8,6,6,24,16,60,10,0,0,0,144,576,2016,2700,0,384,5120,0,0,0,0, %T A014257 24696,21600,0,18816,691200,0,0,1032192,11757312,27993600,6096384, %U A014257 39191040,64012032,15240960,0,387072000,0,0,0,0,0,0,0,0,0,125971200,0,4180377600,0,0,0 %N A014257 Product of digits of 2^n. %t A014257 Array[ Times @@ IntegerDigits[ 2^# ]&, 100 ] %o A014257 (PARI) a(n) = vecprod(digits(2^n)); \\ _Michel Marcus_, Nov 18 2019 %Y A014257 Cf. A000079, A007377. %K A014257 nonn,base,easy %O A014257 0,2 %A A014257 _N. J. A. Sloane_ %E A014257 More terms from _Michel Marcus_, Nov 18 2019