cp's OEIS Frontend

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.

A265350 Numbers whose factorial base representation (A007623) contains at least one of the nonzero digits occurs more than once (although not necessarily in adjacent positions).

This page as a plain text file.
%I A265350 #22 Jan 24 2024 01:50:38
%S A265350 3,7,8,9,11,15,16,17,21,25,26,27,29,30,31,32,33,34,35,37,38,39,40,41,
%T A265350 43,44,45,47,51,52,53,55,56,57,58,59,60,61,62,63,64,65,69,70,71,75,79,
%U A265350 80,81,83,87,88,89,90,91,92,93,94,95,99,103,104,105,107,111,112,113,117,121,122,123,125,126,127,128,129,130
%N A265350 Numbers whose factorial base representation (A007623) contains at least one of the nonzero digits occurs more than once (although not necessarily in adjacent positions).
%C A265350 Positions of terms larger than ones in A264990.
%H A265350 Antti Karttunen, <a href="/A265350/b265350.txt">Table of n, a(n) for n = 1..10080</a>
%H A265350 Indranil Ghosh, <a href="/A265350/a265350.txt">Python program for computing this sequence</a>.
%H A265350 <a href="/index/Fa#facbase">Index entries for sequences related to factorial base representation</a>.
%e A265350 For n=7 the factorial base representation (A007623) is "101" as 7 = 3!+1! = 6+1. Digit "1" occurs twice in it, thus 7 is included in this sequence.
%t A265350 q[n_] := Module[{k = n, m = 2, r, s = {}}, While[{k, r} = QuotientRemainder[k, m]; k != 0|| r != 0, AppendTo[s, r]; m++]; Max[Tally[Select[s, # > 0 &]][[;;,2]]] > 1]; Select[Range[130], q] (* _Amiram Eldar_, Jan 24 2024 *)
%o A265350 (Scheme, with _Antti Karttunen_'s IntSeq-library)
%o A265350 (define A265350 (MATCHING-POS 1 1 (lambda (n) (> (A264990 n) 1))))
%Y A265350 Cf. A007623, A264990.
%Y A265350 Cf. A265349 (complement).
%Y A265350 Cf. A007489, A046807 (subsequences from 3 onward).
%K A265350 nonn,base
%O A265350 1,1
%A A265350 _Antti Karttunen_, Dec 22 2015