A287330 7*x - 1 Collatz-type sequence starting with a(0) = 11.

11, 76, 38, 19, 132, 66, 33, 230, 115, 804, 402, 201, 1406, 703, 4920, 2460, 1230, 615, 4304, 2152, 1076, 538, 269, 1882, 941, 6586, 3293, 23050, 11525, 80674, 40337, 282358, 141179, 988252, 494126, 247063, 1729440, 864720, 432360, 216180, 108090, 54045, 378314, 189157, 1324098

Offset

0,1

Links

Table of n, a(n) for n=0..44.

Formula

a(0) = 11; a(n) = 7*a(n - 1) - 1 if a(n - 1) is odd, a(n) = a(n - 1)/2 if a(n - 1) is even.

Example

11 is odd, so it's followed by 7*11 - 1 = 76.
76 is even, so it's followed by 76/2 = 38.

Mathematica

NestList[If[OddQ[#], 7# - 1, #/2] &, 11, 50]

Crossrefs

Cf. A063871.

Sequence in context: A347987 A157232 A305661 * A282384 A092225 A282816

Adjacent sequences: A287327 A287328 A287329 * A287331 A287332 A287333

Keyword

nonn,easy

Author

Alonso del Arte, Sep 01 2017

Status

approved