A117828 Start with 1 and repeatedly reverse the decimal digits and add 4 to get the next term.

1, 5, 9, 13, 35, 57, 79, 101, 105, 505, 509, 909, 913, 323, 327, 727, 731, 141, 145, 545, 549, 949, 953, 363, 367, 767, 771, 181, 185, 585, 589, 989, 993, 403, 308, 807, 712, 221, 126, 625, 530, 39, 97, 83, 42, 28, 86, 72, 31, 17, 75, 61, 20, 6, 10, 5, 9, 13, 35, 57, 79, 101, 105, 505, 509, 909, 913, 323, 327, 727, 731

Offset

1,2

Links

Table of n, a(n) for n=1..71.

N. J. A. Sloane and others, Sequences of RADD type, OEIS wiki.

Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).

Formula

After one step enters a cycle of length 54: see A117827, A117830.

Maple

read transforms; t1:=[1]; for n from 1 to 80 do t1:=[op(t1), 4+digrev(t1[n])]; od: # N. J. A. Sloane

Mathematica

f[n_] := 4 + FromDigits@ Reverse@ IntegerDigits@n; NestList[ f@# &, 1, 57] (* and *)
(* to view the cycle *) NestWhileList[ f@# &, 1, UnsameQ, All] (* Robert G. Wilson v, May 09 2006 *)

Prog

(PARI) a(n)=if(n>1, my(t=6); for(k=1, n%54, t=fromdigits(Vecrev(digits(t)))+4); t, 1) \\ Charles R Greathouse IV, Nov 07 2016

Crossrefs

Cf. A117827, A117829, A117830.

Sequence in context: A024950 A180514 A118837 * A117830 A376490 A191219

Adjacent sequences: A117825 A117826 A117827 * A117829 A117830 A117831

Keyword

nonn,base,easy

Author

Luc Stevens (lms022(AT)yahoo.com), Apr 06 2006

Status

approved