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.

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

0,2

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.

Links

Table of n, a(n) for n=0..99.

Example

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.

Mathematica

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

Crossrefs

Cf. A277215, A277874.

Sequence in context: A364092 A295294 A317936 * A357157 A317935 A360439

Adjacent sequences: A277872 A277873 A277874 * A277876 A277877 A277878

Keyword

nonn

Author

Hartmut F. W. Hoft, Nov 03 2016

Status

approved