cp's OEIS Frontend

A226277 Numbers m of the form u^v where u and v are digits in decimal representation of m.

%I A226277 #3 Jul 09 2013 15:00:37
%S A226277 1,25,3125,4096,15625,19683,46656,59049,78125,117649,279936,1953125,
%T A226277 4782969,5764801,10077696,387420489
%N A226277 Numbers m of the form u^v where u and v are digits in decimal representation of m.
%C A226277 a(n) occurs in a(n)-th row of table A226272.
%e A226277 a(1) = 1 = 1^1;
%e A226277 a(2) = 25 = 5^2;
%e A226277 a(3) = 3125 = 5^5;
%e A226277 a(4) = 4096 = 4^6;
%e A226277 a(5) = 15625 = 5^6;
%e A226277 a(6) = 19683 = 3^9;
%e A226277 a(7) = 46656 = 6^6;
%e A226277 a(8) = 59049 = 9^5;
%e A226277 a(9) = 78125 = 5^7;
%e A226277 a(10) = 117649 = 7^6;
%e A226277 a(11) = 279936 = 6^7;
%e A226277 a(12) = 1953125 = 5^9;
%e A226277 a(13) = 4782969 = 9^7;
%e A226277 a(14) = 5764801 = 7^8;
%e A226277 a(15) = 10077696 = 6^9;
%e A226277 a(16) = 387420489 = 9^9.
%e A226277 256 = 2^8 = 4^4 is not a term, as neither 8 nor 4 occur in 256.
%o A226277 (Haskell)
%o A226277 import Data.List (sort)
%o A226277 a226277 n = a226277_list !! (n-1)
%o A226277 a226277_list = sort [w | u <- [0..9], v <- [0..9], let w = u ^ v,
%o A226277    "0123456789" !! u `elem` show w, "0123456789" !! v `elem` show w]
%K A226277 nonn,base,fini,full
%O A226277 1,2
%A A226277 _Reinhard Zumkeller_, Jul 09 2013