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 A066460 #13 Jun 21 2025 12:50:04 %S A066460 1,3,7,15,24,40,60,144,120,180,336,420,360,900,960,720,840,1260,1440, %T A066460 2340,1680,2880,3600,8190,2520,9072,9900,6300,6720,20592,5040,10920, %U A066460 7560,31320,98040,25920,10080,21420,177156,74256,15120,28560,20160 %N A066460 a(n) is the least positive integer k such that k is a repdigit number in exactly n different bases B, where 1<B<k. %C A066460 All numbers n are repdigit in base 1 and in all bases greater than n, therefore we restrict the sequence to bases between 1 and n exclusively. %H A066460 Giovanni Resta, <a href="/A066460/b066460.txt">Table of n, a(n) for n = 0..100</a> %e A066460 a(4) = 24 since 24_10 = 44_5 = 33_7 = 22_11 = 11_23. %t A066460 rp[n_, b_] := 1 == Length@ Union@ IntegerDigits[n, b]; c[1] = c[2] = 0; c[n_] := c[n] = Block[{q = Floor@Sqrt@n}, 1 + Length@ Select[Range[2, q], rp[n, #] &] + Length@ Select[Divisors[n] - 1, q < # <= n/2 && rp[n, #] &]]; a[n_] := Block[{k = 1}, While[c[k] != n, k++]; k]; Table[a[j], {j, 0, 30}] (* _Giovanni Resta_, Apr 07 2017 *) %Y A066460 Cf. A066044, A284758. %K A066460 nonn %O A066460 0,2 %A A066460 _Robert G. Wilson v_, Jan 02 2002 %E A066460 Edited by _John W. Layman_, Jan 16 2002 %E A066460 a(0) changed to 1 by _Giovanni Resta_, Apr 07 2017