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.

Showing 1-1 of 1 results.

A277875 a(n) is the odd multiplier q in the expressions 2*(q*2^n - 1) and 2*(q*3^n - 1) of numbers A277215(n) and A277874(n), respectively.

Original entry on oeis.org

1, 7, 1, 1, 1, 19, 13, 1, 1, 1, 1, 7, 5, 11, 1, 1, 1, 7, 11, 1, 1, 1, 1, 1, 1, 7, 5, 1, 1, 7, 1, 1, 1, 1, 1, 11, 5, 1, 1, 1, 1, 1, 1, 1, 1, 7, 5, 1, 1, 7, 1, 1, 1, 7, 1, 1, 1, 7, 5, 11, 1, 7, 5, 1, 1, 7, 1, 1, 1, 11, 1, 1, 1, 1, 1, 11, 1, 7, 1, 1, 1, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 1
Offset: 0

Views

Author

Hartmut F. W. Hoft, Nov 03 2016

Keywords

Comments

The position numbers for odd numbers 5, 7, 11, 13 and 19 for the first 200 numbers in the sequence are listed in the Comments section of A277215.

Examples

			a(0) = 1 since 0 = 2*(1*2^0 - 1) is the start and end of the first alternating sequence of 1 element and the maximum of its trajectory.
a(5) = 19 since 9232 = 2*(19*3^5 - 1) is the last element in the first alternating sequence of 11 elements - 1214, 607, 1822, 911, 2734, 1367, 4102, 2051, 6154, 3077, 9232 - that ends in the trajectory maximum.
		

Crossrefs

Programs

  • Mathematica
    (* we use function altdata[] from A277215 *)
    a277875[n_]:=Map[#[[2]]&, altdata[2,n]]
    Join[{1,7}, a277875[99]] (* sequence data *)
Showing 1-1 of 1 results.