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 A091582 #14 Feb 16 2025 08:32:52 %S A091582 1,1,2,3,5,7,11,15,22,30,56,1002,10143,75175,451276,2323520,10619863, %T A091582 44108109,169229875,214481126,679903203,2056148051,5964539504, %U A091582 16670689208,45060624582,118159068427,301384802048,749474411781,1820701100652,4714566886083,10963707205259 %N A091582 Number of partitions of the n-th decimal palindrome. %H A091582 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PalindromicNumber.html">Palindromic Number</a> %H A091582 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Partition.html">Partition</a> %F A091582 a(n) = A000041(A002113(n)). %o A091582 (Python) %o A091582 from sympy import npartitions %o A091582 def A091582(n): %o A091582 if n == 1: return 1 %o A091582 y = 10*(x:=10**(len(str(n>>1))-1)) %o A091582 return npartitions((c:=n-x)*x+int(str(c)[-2::-1]or 0) if n<x+y else (c:=n-y)*y+int(str(c)[-1::-1]or 0)) # _Chai Wah Wu_, Jun 14 2024 %Y A091582 Cf. A000041, A002113, A091584, A091583. %K A091582 nonn,base %O A091582 1,3 %A A091582 _Reinhard Zumkeller_, Jan 22 2004 %E A091582 a(1)=1 prepended and more terms from _Georg Fischer_, Dec 15 2020