

A082010


a(n) = n/2 if n is even, otherwise floor(8*n/5)+1.


3



0, 2, 1, 5, 2, 9, 3, 12, 4, 15, 5, 18, 6, 21, 7, 25, 8, 28, 9, 31, 10, 34, 11, 37, 12, 41, 13, 44, 14, 47, 15, 50, 16, 53, 17, 57, 18, 60, 19, 63, 20, 66, 21, 69, 22, 73, 23, 76, 24, 79, 25, 82, 26, 85, 27, 89, 28, 92, 29, 95, 30, 98, 31, 101, 32, 105, 33, 108, 34, 111, 35, 114, 36, 117
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,2


COMMENTS

See A152199 for the orbit of 7 under this map (which includes the orbit of 3, 5, 6, 7, 9, ... as well).  M. F. Hasler, Jun 12 2012
This is the 8/5 map, a particular case of the m/n sequence mentioned by Yasutoshi Kohmoto on the SeqFan list (cf. link), which also includes the Collatz map A014682 (for m/n = 3/2).  M. F. Hasler, Jun 12 2012


LINKS

Table of n, a(n) for n=0..73.
Yasutoshi Kohmoto, 8/5 Sequence, SeqFan list, Sep 30 2009
OEIS wiki, m/n sequences, M. F. Hasler, Jun 12 2012
Index entries for linear recurrences with constant coefficients, signature (0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1).


FORMULA

a(n) = +a(n2) +a(n10) a(n12). G.f.: x*(1+x+x^2)*(x^8+2*x^6x^5+2*x^4+2*x^2x+2) / ( (1+x+x^2+x^3+x^4)*(x^4x^3+x^2x+1)*(x1)^2*(1+x)^2 ).  R. J. Mathar, Feb 20 2011


MATHEMATICA

Table[If[EvenQ[n], n/2, Floor[(8n)/5+1]], {n, 0, 80}] (* or *) LinearRecurrence[ {0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1}, {0, 2, 1, 5, 2, 9, 3, 12, 4, 15, 5, 18}, 80] (* Harvey P. Dale, Dec 18 2012 *)


PROG

(PARI) A082010(x)=if(bittest(x, 0), 8*x\5+1, x\2) \\ M. F. Hasler, Jun 12 2012


CROSSREFS

Sequence in context: A111361 A257971 A205377 * A318972 A341495 A337943
Adjacent sequences: A082007 A082008 A082009 * A082011 A082012 A082013


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Oct 06 2009, suggested by postings to the Sequence Fans Mailing List by Yasutoshi Kohmoto and Franklin T. AdamsWatters, Sep 30 2009


STATUS

approved



