Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #8 Feb 24 2013 18:25:41
%S 4,8,18,46,76,107,126,101,84,0,0
%N Number of n-digit perfect powers with distinct digits.
%C Of 1110 perfect powers < 1000000, 259 have distinct digits.
%C For large number of digits, the distinct-digit pp's consists of surprisingly small part of all pp's (shown in brackets) 4(4), 8(8), 18(28), 46(84), 76(242), 107(744), 126(2284), 101(7096), 84(22179), 0(69561).
%e a(3)=18 because there are exactly 18 three-digit perfect powers: 125, 128, 169, 196, 216, 243, 256, 289, 324, 361, 512, 529, 576, 625, 729, 784, 841, 961.
%Y Cf. A001597.
%K fini,full,nonn,base
%O 1,1
%A _Zak Seidov_, Oct 13 2002