A191304 Records in A132199.

1, 5, 11, 23, 47, 101, 233, 467, 941, 1889, 3779, 7559, 15131, 30323, 60647, 121403, 242807, 486041, 972533, 1945649, 3891467, 7783541, 15567089, 31139561, 62279171, 124559609, 249120239, 498270791, 996541661, 1993083437, 3986167223, 7972334723, 15944673761

Offset

1,2

Comments

Except for a(1)=1, log(a(n)) is nearly but not exactly linear. - Ralf Steiner, Aug 18 2017

Links

Ralf Steiner, Table of n, a(n) for n = 1..171

Formula

For all a(n) except a(1)=1 is 5 congruent mod 6, a(n+1) > 2 a(n) and lim_{n->inf} a(n+1)/a(n) = 2. - Ralf Steiner, Aug 18 2017

Mathematica

Union@ FoldList[Max, Rest@ # - Most@ #] &@ FoldList[#1 + GCD[#2, #1] &, 7, Range[2, 10^7]] (* Michael De Vlieger, Aug 19 2017, after Robert G. Wilson v at A132199 *)

Crossrefs

Cf. A106108, A132199, A137613.

Sequence in context: A362082 A306662 A052940 * A102444 A132177 A340340

Adjacent sequences: A191301 A191302 A191303 * A191305 A191306 A191307

Keyword

nonn

Author

Robert G. Wilson v, Apr 30 2009

Extensions

a(23)-a(33) from Ralf Steiner, Aug 18 2017

Status

approved