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A113621 Numbers n such that the representation of n^2 is a substring of that of n!, in base 10. 0
1, 20, 29, 170, 176, 241, 3136, 9800, 20309, 20486, 53663, 73793, 94836, 200000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Using one of the fast algorithms for computing the last nonzero digit of the factorial (A008904) it is easy to see that also 200000000 and 2*10^16 are terms.

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

29^2 = 841 and 29! = 8(841)761993739701954543616000000.

MATHEMATICA

lst={}; Do[If[{}!= StringPosition[ToString[n! ], ToString[n^2]], AppendTo[lst, n]], {n, 10000}]; lst

CROSSREFS

Cf. A033180, A008904.

Sequence in context: A039286 A043889 A303080 * A166676 A125561 A171908

Adjacent sequences:  A113618 A113619 A113620 * A113622 A113623 A113624

KEYWORD

base,nonn,more

AUTHOR

Giovanni Resta, Jan 26 2006

EXTENSIONS

Extended by Giovanni Resta, Apr 04 2014

STATUS

approved

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Last modified April 16 23:40 EDT 2021. Contains 343051 sequences. (Running on oeis4.)