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A078670
Number of times n appears among the decimal digits of (n!)!.
0
1, 1, 0, 4, 21, 169, 1504, 15755, 177333, 213789
OFFSET
1,4
EXAMPLE
a(4)=4 because 4 appears four times in (4!)! = 620448401733239439360000.
MATHEMATICA
Table[Count[Partition[IntegerDigits[(n!)!], IntegerLength[n], 1], IntegerDigits[ n]], {n, 10}] (* Harvey P. Dale, May 19 2014 *)
Table[SequenceCount[IntegerDigits[(n!)!], IntegerDigits[n]], {n, 10}] (* The program uses the SequenceCount function from Mathematica version 10 *) (* Harvey P. Dale, Aug 08 2016 *)
PROG
(PARI) {mdcp(d, n)=local(a, c=0, L); L=length(Str(d)); if(L>1, a=2, a=1); while(n>0, if(n%(10^a)==d, n=floor(n/10); c++, n=floor(n/10); )); c } for(n=1, 10, print1(mdcp(n, n!!)", "))
CROSSREFS
Cf. A000197.
Sequence in context: A107872 A008858 A217484 * A317104 A163948 A278993
KEYWORD
base,more,nonn
AUTHOR
Jason Earls, Dec 16 2002
EXTENSIONS
Added a(9) and a(10). - Ryan Leonel (ryan.leonel(AT)gmail.com), Oct 03 2008
STATUS
approved