cp's OEIS Frontend

A254501 a(n) is the smallest nonnegative integer such that a(n)! contains a string of exactly n consecutive 6's.

%I A254501 #38 Mar 21 2019 13:26:40
%S A254501 0,3,20,38,35,213,1122,3415,10214,32430,145197,351679,666779,813843,
%T A254501 3765934
%N A254501 a(n) is the smallest nonnegative integer such that a(n)! contains a string of exactly n consecutive 6's.
%e A254501 a(1) = 3 since 3! equals 6 and contains '6'.
%e A254501 a(2) = 20 since 20! contains '66' and 20 is the smallest integer for which the condition is met.
%t A254501 A254451[n_] := Module[{m = 0},
%t A254501    If[n == 0, While[MemberQ[IntegerDigits[m!], 6], m++]; m,
%t A254501     t = Table[6, n];
%t A254501     While[! MemberQ[Split[IntegerDigits[m!]], t], m++]; m]];
%t A254501 Table[A254451[n], {n, 0, 7}] (* _Robert Price_, Mar 21 2019 *)
%Y A254501 Cf. A254042, A254447, A254448, A254449, A254500, A254502, A254716, A254717.
%K A254501 nonn,base,more
%O A254501 0,2
%A A254501 _Martin Y. Champel_, Jan 31 2015
%E A254501 a(10), a(11) from _Jon E. Schoenfield_, Feb 21 2015, Feb 23 2015
%E A254501 a(0) prepended by _Jon E. Schoenfield_, Mar 01 2015
%E A254501 a(12), a(13) from _Jon E. Schoenfield_, Mar 07 2015, Mar 10 2015
%E A254501 a(14) from _Bert Dobbelaere_, Oct 29 2018