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 A112875 #11 Jun 14 2024 08:48:56 %S A112875 0,1,2,3,4,5,6,7,8,9,1,4,9,16,25,36,49,64,81,0,1,2,3,4,5,6,7,8,9,0,4, %T A112875 8,12,16,20,24,28,32,36,0,9,18,27,36,45,54,63,72,81,0,16,32,48,64,80, %U A112875 96,112,128,144,0,25,50,75,100,125,150,175,200,225,0,36,72,108,144,180,216 %N A112875 Product of digits of n-th base 10 palindrome. %F A112875 a(n) = A007954(A002113(n)). - _Michel Marcus_, Jun 14 2024~ %o A112875 (Python) %o A112875 from math import prod %o A112875 def A112875(n): %o A112875 if n == 1: return 0 %o A112875 y = 10*(x:=10**(len(str(n>>1))-1)) %o A112875 return int((s:=str(n-x))[-1])*prod(int(d) for d in s[:-1])**2 if n<x+y else prod(map(int,str(n-y)))**2 # _Chai Wah Wu_, Jun 14 2024 %Y A112875 Cf. A002113, A007954. %K A112875 base,easy,nonn %O A112875 1,3 %A A112875 _Giovanni Teofilatto_, Jan 02 2006 %E A112875 More terms from _Joshua Zucker_, May 03 2006