cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A155167 (L)-sieve transform of A004767 = {3,7,11,15,...,4n-1,...}.

Original entry on oeis.org

1, 2, 3, 5, 7, 10, 14, 19, 26, 35, 47, 63, 85, 114, 153, 205, 274, 366, 489, 653, 871, 1162, 1550, 2067, 2757, 3677, 4903, 6538, 8718, 11625, 15501, 20669, 27559, 36746, 48995, 65327, 87103, 116138, 154851, 206469
Offset: 1

Views

Author

John W. Layman, Jan 21 2009

Keywords

Comments

See A152009 for the definition of the (L)-sieve transform.
This appears to be the same sequence that is defined in Problem 193 of Popular Computing, Number 55 (see link). - N. J. A. Sloane, Apr 16 2015

Crossrefs

Programs

  • Maple
    # Maple program for Popular Computing Problem 193, which produces terms which appear to match this sequence, from N. J. A. Sloane, Apr 16 2015
    with(LinearAlgebra): M:=1000;  B:=300;
    t1:=Array(1..M,0); t2:=Array(1..M,0); t3:=Array(1..M,-1);
    for n from 1 to M do t1[n]:=n+2; od:
    for n from 1 to B do
    i:=t1[1];
    if t3[i] = -1 then t3[i]:=n-1; fi;
    for j from 1 to i do t2[j]:=t1[j+1]; od:
    t2[i+1]:=i;
    for p from i+2 to M-2 do t2[p]:=t1[p]; od;
    for q from 1 to M-2 do t1[q]:=t2[q]; od:
    od:
    [seq(t3[n],n=3..B)];
  • Mathematica
    NestList[Floor[(4#+3)/3]&,1,40] (* Harvey P. Dale, Oct 04 2021 *)

Formula

All listed terms satisfy the recurrence a(n) = floor((4*a(n-1)+3)/3), with a(1)=1.