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 A138707 #5 Feb 16 2025 08:33:08
%S A138707 1,2,2,3,2,4,2,4,3,4,1,2,1,2,2,2,1,2,1,6,1,2,1,3,2,2,1,3,1,8,1,2,2,2,
%T A138707 2,4,1,2,2,8,1,2,1,3,2,2,1,4,1,6,1,2,1,2,2,2,1,2,1,12,1,2,2,3,2,4,1,3,
%U A138707 2,8,1,2,1,2,2,2,2,2,1,10,1,2,1,3,2,2,1,4,1,12,1,2,2,2,2,4,1,2,3,9,1,2,1,3
%N A138707 Number of divisors of n that are also divisors of some d(k)*10^k, where n=Sum(d(k)*10^k).
%C A138707 a(A138708(n)) = 1; a(A037124(n)) = A000005(A037124(n)).
%H A138707 R. Zumkeller, <a href="/A138707/b138707.txt">Table of n, a(n) for n = 1..10000</a>
%H A138707 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DivisorFunction.html">Divisor Function</a>
%e A138707 n = 216 = 2*10^2 + 1*10^1 + 6*10^0: let D(n) = set of divisors of
%e A138707 n,
%e A138707 D(216)={1,2,3,4,6,8,9,12,18,24,27,36,54,72,108,216},
%e A138707 D(200)={1,2,4,5,8,10,20,25,40,50,100,200}, D(10)={1,2,5,10}, D(6)={1,2,3,6},
%e A138707 a(216) = #{1,2,3,4,6,8} = 6.
%Y A138707 Cf. A061116.
%K A138707 nonn,base
%O A138707 1,2
%A A138707 _Reinhard Zumkeller_, Mar 26 2008