The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A227508

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A227508

Numbers n such that n! is divisible by R(n), the digit reversal of n.
(history; published version)

#9 by Bruno Berselli at Sun Jul 21 02:24:01 EDT 2013

STATUS

reviewed

approved

#8 by R. J. Mathar at Sat Jul 20 12:16:35 EDT 2013

STATUS

proposed

reviewed

#7 by R. J. Mathar at Sat Jul 20 12:16:31 EDT 2013

STATUS

editing

proposed

#6 by R. J. Mathar at Sat Jul 20 12:16:12 EDT 2013

NAME

Numbers n such that n! is divisible by R(n) = , the digit reversal of n.

MAPLE

read("transforms"):

isA227508 := proc(n)

if modp(n!, digrev(n)) = 0 then

true;

else

false ;

end if;

end proc:

A227508 := proc(n)

if n = 1 then

1;

else

for a from procname(n-1)+1 do

if isA227508(a) then

return a;

end if;

end do:

end if;

end proc: # R. J. Mathar, Jul 20 2013

STATUS

proposed

editing

#5 by Joerg Arndt at Sun Jul 14 02:56:33 EDT 2013

STATUS

editing

proposed

#4 by Joerg Arndt at Sun Jul 14 02:56:13 EDT 2013

NAME

Numbers n such that n! is divisible by R (n) = digit reversal of n.

COMMENTS

Numbers n for which A004086 (n) divides A000142 (n).

STATUS

proposed

editing

#3 by Jayanta Basu at Sun Jul 14 02:18:45 EDT 2013

STATUS

editing

proposed

#2 by Jayanta Basu at Sun Jul 14 02:18:27 EDT 2013

NAME

allocated for Jayanta BasuNumbers n such that n! is divisible by R (n) = digit reversal of n.

DATA

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 18, 19, 20, 21, 22, 23, 24, 25, 27, 29, 30, 31, 32, 33, 36, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78

OFFSET

1,2

COMMENTS

Numbers n for which A004086 (n) divides A000142 (n).

EXAMPLE

12 is a member since R(12)=21 divides 12! while 13 is not a member as 31 does not divide 13!.

MATHEMATICA

Select[Range[79], Divisible[#!, FromDigits[Reverse[IntegerDigits[#]]]] &]

CROSSREFS

Cf. A000142, A004086.

KEYWORD

allocated

nonn,base

AUTHOR

Jayanta Basu, Jul 14 2013

STATUS

approved

editing

#1 by Jayanta Basu at Sun Jul 14 02:18:27 EDT 2013

NAME

allocated for Jayanta Basu

KEYWORD

allocated

STATUS

approved