A034874 a(1) = 1; for n >= 2, a(n) = n times the reverse of a(n-1).

1, 2, 6, 24, 210, 72, 189, 7848, 76383, 383670, 840213, 3744576, 87808149, 1318532292, 43835371965, 910677661344, 7533835192323, 58192476900426, 1185618381154515, 103090236763316220, 474880720273896321, 2721364184595946428, 189669406960736519256

Offset

1,2

Comments

A004086(a(n)) = A096138(n). [Reinhard Zumkeller, Jan 02 2012]

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..250

Index entries for sequences related to factorial numbers

Maple

digrev:= proc(x) local L, j;
   L:= convert(x, base, 10);
   add(L[-i]*10^(i-1), i=1..nops(L));
end proc:
A[1]:= 1:
for n from 2 to 30 do A[n]:= n*digrev(A[n-1]) od:
seq(A[n], n=1..30); # Robert Israel, Feb 01 2015

Mathematica

nxt[{n_, a_}]:={n+1, IntegerReverse[a](n+1)}; Transpose[NestList[nxt, {1, 1}, 20]] [[2]] (* The program uses the IntegerReverse function from Mathematica version 10 *) (* Harvey P. Dale, Apr 21 2016 *)

Prog

(Haskell)
a034874 n = a034874_list !! (n-1)
a034874_list = 1 : f 2 1 where
   f x y = z : f (x + 1) z where z = (x * a004086 y)
-- Reinhard Zumkeller, Jan 02 2012
(Python)
A034874_list, a = [1], 1
for n in range(2, 100):
....a = n*int(str(a)[::-1])
....A034874_list.append(a) # Chai Wah Wu, Feb 01 2015

Crossrefs

Cf. A000142, A004086, A096138.

Sequence in context: A356575 A347895 A355284 * A052699 A074351 A352060

Adjacent sequences: A034871 A034872 A034873 * A034875 A034876 A034877

Keyword

easy,nonn,base,nice

Author

Erich Friedman

Status

approved