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 A254318 #21 Feb 06 2015 05:50:34 %S A254318 2,3,4,5,7,10,11,12,13,14,15,16,17,18,19,20,21,23,24,25,28,29,31,32, %T A254318 35,36,37,39,41,43,46,47,49,50,53,54,58,59,61,64,67,69,71,72,73,79,81, %U A254318 83,89,92,93,97,98,100,101,103,104,105,106,107,109,113,116,119 %N A254318 Hyper equidigital numbers. %C A254318 The distinction between the equidigital numbers (A046758) is that only the distinct digits are counted instead of all digits. Hence the definition: %C A254318 Write n as product of primes raised to powers, let D(n) = total number of distinct digits in product representation (number of distinct digits in all the primes and number of distinct digits in all the exponents that are greater than 1) and nbd(n) = A043537(n) = number of distinct digits in n; sequence gives n such that D(n) = nbd(n). %H A254318 Michel Lagneau, <a href="/A254318/b254318.txt">Table of n, a(n) for n = 1..10000</a> %e A254318 116 is in the sequence because 116 = 2^2*29 => D(116)= A043537(116)=2. %t A254318 Cases[Range[400], n_ /; Length[Union[Flatten[IntegerDigits[FactorInteger[n] /. 1 -> Sequence[]]]]]==Length[Union[Flatten[IntegerDigits[n]]]]] %o A254318 (PARI) for(n=1,100,s=[];F=factor(n);for(i=1,#F[,1],s=concat(s,digits(F[i,1]));if(F[i,2]>1,s=concat(s,digits(F[i,2]))));if(#vecsort(digits(n),,8)==#vecsort(s,,8),print1(n,", "))) \\ _Derek Orr_, Jan 30 2015 %Y A254318 Cf. A043537, A046760, A046758, A046759, A254315, A254317, A254319, A254321. %K A254318 nonn,base %O A254318 1,1 %A A254318 _Michel Lagneau_, Jan 28 2015