A254500 a(n) is the smallest nonnegative integer such that a(n)! contains a string of exactly n consecutive 5's.

0, 7, 17, 70, 111, 258, 689, 454, 7133, 15977, 82869, 111044, 536687, 384769, 2750561, 7063105

Offset

0,2

Comments

a(14) > 1500000. - Jon E. Schoenfield, Mar 31 2015

Links

Table of n, a(n) for n=0..15.

Example

a(1) = 7 as 7! equals 5040, which contains '5' and 5 is the smallest integer for which the condition is met.

Mathematica

A254450[n_] := Module[{m = 0},
   If[n == 0, While[MemberQ[IntegerDigits[m!], 5], m++]; m,
    t = Table[5, n];
    While[! MemberQ[Split[IntegerDigits[m!]], t], m++]; m]];
Table[A254450[n], {n, 0, 13}] (* Robert Price, Mar 21 2019 *)

Crossrefs

Cf. A254042, A254447, A254448, A254449, A254501, A254502, A254716, A254717.

Sequence in context: A269239 A118431 A051809 * A242907 A034054 A120876

Adjacent sequences: A254497 A254498 A254499 * A254501 A254502 A254503

Keyword

nonn,more,base

Author

Martin Y. Champel, Jan 31 2015

Extensions

a(12)-a(13) from Jon E. Schoenfield, Feb 27 2015

a(0) prepended by Jon E. Schoenfield, Mar 01 2015

a(14)-a(15) from Bert Dobbelaere, Oct 29 2018

Status

approved