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!)
 A088333 A version of Josephus problem: a(n) is the surviving integer under the following elimination process. Arrange 1,2,3,...,n in a circle, increasing clockwise. Starting with i=1, delete the integer 3 places clockwise from i. Repeat, counting 3 places from the next undeleted integer, until only one integer remains. 3
 1, 1, 2, 2, 1, 5, 2, 6, 1, 5, 9, 1, 5, 9, 13, 1, 5, 9, 13, 17, 21, 3, 7, 11, 15, 19, 23, 27, 2, 6, 10, 14, 18, 22, 26, 30, 34, 38, 3, 7, 11, 15, 19, 23, 27, 31, 35, 39, 43, 47, 51, 3, 7, 11, 15, 19, 23, 27, 31, 35, 39, 43, 47, 51, 55, 59, 63, 67, 2, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS If one counts only one place (resp. two places) at each stage to determine the element to be deleted, we get A006257 (resp. A054995). REFERENCES See A054995 for references and links. LINKS FORMULA It is tempting (in view of A054995) to conjecture that a(1)=1 and, for n>1, a(n) = (a(n-1)+4) mod n. The conjecture is false; counterexample: a(21)=21; a(20)=17; (a(20)+4)mod 21=0; corrected formula: a(n)=(a(n-1)+3) mod n +1; The conjecture is true. After removing the 4th number, we are reduced to the n-1 case, but starting with 5 instead of 1. - David Wasserman, Aug 08 2005 a(n) = A032434(n,4) if n>=4. - R. J. Mathar, May 04 2007 CROSSREFS Cf. A006257, A054995, A032434, A005427, A005428, A006257, A007495, A000960, A056530. Sequence in context: A188945 A281261 A102849 * A016538 A134226 A184050 Adjacent sequences:  A088330 A088331 A088332 * A088334 A088335 A088336 KEYWORD nonn,easy AUTHOR N. J. A. Sloane, Nov 13 2003 EXTENSIONS More terms from David Wasserman, Aug 08 2005 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 27 15:27 EDT 2020. Contains 338035 sequences. (Running on oeis4.)