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 A112375 #11 Mar 15 2020 22:43:04
%S A112375 21,31,22,51,71,23,32,111,131,24,171,191,231,52,33,291,311,25,371,411,
%T A112375 431,471,72,531,591,611,26,671,711,731,791,34,831,891,971,1011,1031,
%U A112375 1071,1091,1131,112,53,1271,27,1311,1371,1391,1491,1511,1571,1631,1671
%N A112375 Concatenation of base and exponent of prime powers.
%C A112375 If n = p^q, where p is prime and q > 0, then p concatenated with q is in the sequence.
%C A112375 Might be a good "puzzle" sequence - guess the rule given the first ten or so terms.
%H A112375 Robert Price, <a href="/A112375/b112375.txt">Table of n, a(n) for n = 1..1280</a>
%F A112375 a(n) = A067599(A246655(n)) = A067599(A000961(n+1)). - _M. F. Hasler_, Mar 14 2018
%e A112375 n = 3 = 3^1, so (3 concatenated with 1) = 31 is a term.
%t A112375 Map[FromDigits, Select[Table[FactorInteger[i], {i, 2, 10000}],
%t A112375 Length[#] == 1 &], 2] (* _Robert Price_, Mar 15 2020 *)
%o A112375 (PARI) for(n=1,300,fac=factor(n);if(matsize(fac)[1]==1,print1(eval(concat(Str(fac[1,1]),Str(fac[1,2]))),",")))
%Y A112375 Cf. A112376, A064438, A067599.
%K A112375 nonn,base
%O A112375 1,1
%A A112375 _Zak Seidov_, Dec 04 2005
%E A112375 Edited and extended by _Klaus Brockhaus_, Jan 21 2006