cp's OEIS Frontend

A337535 For n>1, a(n) is the least base b>2 such that the digits of n in base b contain the digit b-1; a(1)=1.

%I A337535 #32 Jan 01 2021 10:31:35
%S A337535 1,3,4,5,3,3,3,3,5,11,3,4,4,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,3,4,4,3,3,3,
%T A337535 3,37,19,3,4,41,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
%U A337535 3,3,3,3,3,3,3,3,3,3,3,3,3,41,83,3,5,43
%N A337535 For n>1, a(n) is the least base b>2 such that the digits of n in base b contain the digit b-1; a(1)=1.
%C A337535 The choice b>2 in the name of this sequence comes from the fact that base 2 has the desired property for all n>1.
%H A337535 Michel Marcus, <a href="/A337535/b337535.txt">Table of n, a(n) for n = 1..10000</a>
%e A337535 a(4) = 5 since 4 = 4_5, and 5 is the only base b > 2 with digit b-1.
%e A337535 a(7) = 3 since 7 = 21_3 so containing the digit 2.
%o A337535 (PARI) isok(n, b) = vecmax(digits(n, b)) == b-1;
%o A337535 a(n) = if (n==1, return (1)); my(b=3); while(!isok(n, b), b++); b;
%Y A337535 Cf. A337496, A337536.
%K A337535 nonn,base
%O A337535 1,2
%A A337535 _Michel Marcus_, Aug 31 2020