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 A113622 #13 Jun 07 2025 05:21:29
%S A113622 1,21,63,270,291,1065,2991,6102,10087,10279,10654,16528,144069,
%T A113622 1440069,10253179,10657654,14400069,16163608,46676013,69460293,
%U A113622 2346534651,2369436474,6313047393,10270341004,10657657654,14406534069,23400000651
%N A113622 Numbers k such that the reverse of the representation of phi(k) is a substring of k, in base 10.
%C A113622 If p = 480...023 is prime, then k = 3*p = 1440...069 and phi(k) = 960...044, thus k belongs to the sequence.
%e A113622 phi(1_440069) = 960044.
%t A113622 lst = {}; Do[If[{}!= StringPosition[ToString@n, StringReverse@ToString@EulerPhi@n], AppendTo[lst, n]], {n, 2*10^7}]; lst
%Y A113622 Cf. A000010, A069215.
%K A113622 base,nonn
%O A113622 1,2
%A A113622 _Giovanni Resta_, Jan 26 2006
%E A113622 a(19)-a(27) from _Donovan Johnson_, May 11 2010