The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Please make a donation to keep the OEIS running. We are now in our 56th year. In the past year we added 10000 new sequences and reached almost 9000 citations (which often say "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A086398 a(1)=1; a(n)=a(n-1)+2 if n is in the sequence; a(n)=a(n-1)+2 if n and (n-1) are not in the sequence; a(n)=a(n-1)+4 if n is not in the sequence but (n-1) is in the sequence. 3
 1, 5, 7, 9, 11, 15, 17, 21, 23, 27, 29, 33, 35, 37, 39, 43, 45, 49, 51, 53, 55, 59, 61, 65, 67, 69, 71, 75, 77, 81, 83, 85, 87, 91, 93, 97, 99, 103, 105, 109, 111, 113, 115, 119, 121, 125, 127, 129, 131, 135, 137, 141, 143, 147, 149, 153, 155, 157, 159, 163, 165, 169 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Conjecture:  the positions of 1 in the fixed point of the morphism 0 -> 10, 1 -> 1000, and -1 < n*(1 + sqrt(3)) - a(n) < 4 for n>=1; see A285301. - Clark Kimberling, Apr 25 2017 LINKS Clark Kimberling, Table of n, a(n) for n = 1..10000 FORMULA a(n) = (1+sqrt(3))*n + O(1). MATHEMATICA s = Nest[Flatten[# /. {0 -> {1, 0}, 1 -> {1, 0, 0, 0}}] &, {0}, 10]; (* A285301 *) Flatten[Position[s, 0]];  (* A285302 *) Flatten[Position[s, 1]];  (* A086398 *) PROG (PARI) x=1; y=2; z=2; t=4; an[1]=x; for(n=2, 100, an[n]=if(setsearch(Set(vector(n-1, i, a(i))), n), a(n-1)+y, if(setsearch(Set(vector(n-1, i, a(i))), n-1), a(n-1)+t, a(n-1)+z))) CROSSREFS Cf. A086377, A285301, A285302. Sequence in context: A314375 A309747 A080384 * A023380 A076190 A028885 Adjacent sequences:  A086395 A086396 A086397 * A086399 A086400 A086401 KEYWORD nonn AUTHOR Benoit Cloitre, Sep 13 2003 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified November 26 07:49 EST 2020. Contains 338632 sequences. (Running on oeis4.)