The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A056753 Only odd numbers occur and for all k there are k numbers between any two successive occurrences of k. 6
 1, 3, 1, 5, 1, 3, 1, 7, 1, 3, 1, 9, 1, 3, 1, 7, 1, 3, 1, 11, 1, 3, 1, 7, 1, 3, 1, 13, 1, 3, 1, 7, 1, 3, 1, 15, 1, 3, 1, 7, 1, 3, 1, 17, 1, 3, 1, 7, 1, 3, 1, 15, 1, 3, 1, 7, 1, 3, 1, 19, 1, 3, 1, 7, 1, 3, 1, 15, 1, 3, 1, 7, 1, 3, 1, 21, 1, 3, 1, 7, 1, 3, 1, 15, 1, 3, 1, 7, 1, 3, 1, 23, 1, 3, 1, 7, 1, 3, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Only the numbers 2^m - 1 occur more than once. a(A005843(n)) = 1; a(A016813(n)) = 3; a(A004771(n)) = 7; a(A008598(n) + 35) = 15; a(A008598(n) + 155) = 31. - Reinhard Zumkeller, Aug 23 2009 A181497(n) = smallest m such that A056753(m) = 2*n + 1. - Reinhard Zumkeller, Oct 24 2010 LINKS R. Zumkeller, Table of n, a(n) for n = 0..10000 FORMULA Let x = a(n - A164632(n)), a(n) = if (x occured exactly once so far) then x+2 else x. - Reinhard Zumkeller, Aug 23 2009 MATHEMATICA a[n_] := a[n] = (ClearAll[f]; f[i_, x_, y_, z_] := f[i, x, y, z] = If[i == n, If[x == 1, a[n-z] + 2, a[n-z]], If[x == 1, If[y == 1, f[i+1, 2z, z, 2z], f[i+1, z, y-1, z]], f[i+1, x-1, y, z]]]; If[n == 0, 1, f[1, 1, 1, 1]]); Table[a[n], {n, 0, 98}] (* Jean-François Alcover, Dec 14 2011, after Reinhard Zumkeller *) PROG (PolyML) fun A056753(n) =     let fun f(i, x, y, z) =             if i = n              then if x = 1                    then A056753(n - z) + 2                    else A056753(n - z)              else if x = 1                    then if y = 1                          then f(i + 1, 2*z, z, 2*z)                          else f(i + 1, z, y - 1, z)                    else f(i + 1, x - 1, y, z)      in if n = 0          then 1          else f(1, 1, 1, 1)     end; (* Reinhard Zumkeller, Feb 25 2012, Aug 23 2009 *) (MAGMA) S:=[ 0: n in [1..100] ]; k:=1; p:=Position(S, 0, 1); while p gt 0 do for j in [p..#S by k+1] do if S[j] eq 0 then S[j]:=k; else break; end if; end for; f:=p; p:=Position(S, 0, f); k+:=2; end while; S; // Klaus Brockhaus, Oct 25 2010 (Haskell) import Data.List (intercalate, group) a056753 n = a056753_list !! n a056753_list =  ++ odds [] where    odds xs = xs ++ (intercalate xs' \$ group [y+2, y+4..2*y+1]) ++ odds xs'         where y = 2 * length xs + 1               xs' = xs ++ [y] ++ xs -- Reinhard Zumkeller, Feb 25 2012, Oct 24 2010 CROSSREFS Sequence in context: A325523 A016475 A037227 * A243158 A154723 A273262 Adjacent sequences:  A056750 A056751 A056752 * A056754 A056755 A056756 KEYWORD nice,nonn,look AUTHOR Claude Lenormand (claude.lenormand(AT)free.fr), Jan 19 2001 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 October 23 04:06 EDT 2021. Contains 348211 sequences. (Running on oeis4.)