%I #8 Jun 06 2016 08:10:28
%S 7525,7533,251196,264770,304732,1768696,2605292,2653884,32554685,
%T 46415894
%N Numbers x = concat(a,b) such that a^b begins with the digits of x.
%e 7525 is a member because 75^25 is equal to 752543...6875, i.e., its first digits are 7525.
%t beg[x_, y_, n_] := x > 0 && Log10[x]*y >= Log10[n] && Block[{u = FractionalPart@ Log10[n+1]}, FractionalPart@ Log10[n] <= FractionalPart[ Log10[x]*y] < If[u == 0, 1, u]]; ok[n_] := Block[{p=1}, While[(p *= 10) < n && ! beg[Floor[n/p], Mod[n, p], n]]; p < n]; Select[Range[10^6], ok]
%Y Cf. A266817, A266818, A273383.
%K nonn,base,more
%O 1,1
%A _Giovanni Resta_, Jun 06 2016
