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A254502
a(n) is the smallest nonnegative integer such that a(n)! contains a string of exactly n consecutive 7's.
10
0, 6, 31, 48, 22, 599, 1102, 5280, 4667, 1753, 48861, 150336, 223254, 644487, 7016773, 9588848
OFFSET
0,2
EXAMPLE
a(1) = 6 since 6! equals 720, which contains '7'.
MATHEMATICA
A254452[n_] := Module[{m = 0},
If[n == 0, While[MemberQ[IntegerDigits[m!], 7], m++]; m,
t = Table[7, n];
While[! MemberQ[Split[IntegerDigits[m!]], t], m++]; m]];
Table[A254452[n], {n, 0, 14}] (* Robert Price, Mar 21 2019 *)
KEYWORD
nonn,base,more
AUTHOR
Martin Y. Champel, Jan 31 2015
EXTENSIONS
a(11), a(12) from Jon E. Schoenfield, Feb 21 2015
a(0) prepended by Jon E. Schoenfield, Mar 01 2015
a(13) from Jon E. Schoenfield, Mar 06 2015
a(14)-a(15) from Bert Dobbelaere, Oct 29 2018
STATUS
approved