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 A162943 #9 Mar 31 2021 03:01:38 %S A162943 1,2,4,4,8,4,8,8,8,4,8,8,16,8,4,4,8,8,16,16,8,4,8,8,8,4,4,4,8,16,32, %T A162943 32,16,8,4,4,8,4,2,2,4,8,16,16,16,8,16,16,16,16,8,8,16,16,8,8,4,2,4,4, %U A162943 8,4,4,4,2,4,8,8,4,8,16,16,32,16,16,16,8 %N A162943 a(n) = 2^(1-A002321(n)). %o A162943 (Python) %o A162943 from functools import lru_cache %o A162943 @lru_cache(maxsize=None) %o A162943 def A162943(n): %o A162943 if n == 0: %o A162943 return 2 %o A162943 c, j = n, 2 %o A162943 k1 = n//j %o A162943 while k1 > 1: %o A162943 j2 = n//k1 + 1 %o A162943 c += (j2-j)*(4-len(bin(A162943(k1)))) %o A162943 j, k1 = j2, n//j2 %o A162943 return 2**(1+c-j) # _Chai Wah Wu_, Mar 30 2021 %Y A162943 Cf. A002321, first column of A162944. %K A162943 nonn %O A162943 1,2 %A A162943 _Mats Granvik_, Jul 18 2009