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 A222812 #19 Jun 29 2023 11:20:49 %S A222812 0,18,329,5000,65931,779504,8517616,88555255,897147508,8997325290, %T A222812 90000000000,900000000000,9000000000000,90000000000000, %U A222812 900000000000000,9000000000000000,90000000000000000,900000000000000000,9000000000000000000,90000000000000000000 %N A222812 Number of n-digit numbers N such that the number formed by some nontrivial permutation of the digits of N divides N. %C A222812 Suggested by A214927. %H A222812 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (10). %F A222812 a(n) = 9 * 10^(n-1) for n >= 11. - _Hiroaki Yamanouchi_, Sep 03 2014. %F A222812 G.f.: x^2*(26747100*x^9 +25850210*x^8 +11594958*x^7 +3379095*x^6 +722576*x^5 +120194*x^4 +15931*x^3 +1710*x^2 +149*x +18)/(1-10*x). - _Robert Israel_, Sep 03 2014 %e A222812 Some of the smallest solutions are: %e A222812 [10, 11, 20, 22, 30, 33, 40, 44, 50, 55, 60, 66, 70, 77, 80, 88, 90, 99] (so a(2) = 18), %e A222812 [100, 101, 105, 108, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 130, 131, 133, 140, 141, 144, 150, 151, 155, 160, 161, 166, 170, 171, 177, 180, 181, 188, 190, 191, 199, 200, 202, 210, 211, 212, 220, 221, 222, 223, 224, ...] %e A222812 Note that 11 is in the sequence because permuting the two digits gives 11, and 11 divides 11. %Y A222812 Cf. A214927, A222809, A222810, A222811. %K A222812 nonn,base %O A222812 1,2 %A A222812 _N. J. A. Sloane_, Mar 10 2013 %E A222812 a(7)-a(20) from _Hiroaki Yamanouchi_, Sep 03 2014