A106372 - OEIS

%I #12 Nov 05 2017 14:37:33

%S 1,2,6,12,20,60,147,384,896,360,1540,2760,2304,11016,13860,6720,

%T 123060,255024,658370,1422720,1425606,1179360,2920500,12252240,

%U 9989280,24227280,242573760,68424048,990208128,410810400,602751600

%N Smallest number m containing no zeros in base n representation but at least one zero in all base b representations with 1<b<n.

%C A106370(a(n)) = n and A106370(m) <> n for m < a(n).

%C a(46) = 854710136280. a(45) and all further terms are at least 10^13.

%H Michael Gottlieb, <a href="/A106372/b106372.txt">Table of n, a(n) for n = 2..44</a> (terms 2..32 from Reinhard Zumkeller, terms 33..44 from Michael Gottlieb).

%H Michael Gottlieb, <a href="/A106372/a106372.cpp.txt">C++ program to compute values.</a>

%e a(10)=896, A106370(896)=10: 896[base-9]='1205',

%e 896[octal]='1600', 896[base-7]='2420', 896[base-6]='4052',

%e 896[base-5]='12041', 896[base-4]='32000', 896[ternary]='1020012',

%e 896[binary]='1110000000'.

%o (Haskell)

%o import Data.List (elemIndex); import Data.Maybe (fromJust)

%o a106372 = (+ 1) . fromJust . (`elemIndex` a106370_list)

%o -- _Reinhard Zumkeller_, Apr 12 2015

%Y Cf. A106370, A119354.

%K nonn,base

%O 2,2

%A _Reinhard Zumkeller_, May 01 2005

%E Generated a(33)-a(44) and a(46), with linked C++ program