A090691 5x - 1 sequence starting at 50.

50, 25, 124, 62, 31, 154, 77, 384, 192, 96, 48, 24, 12, 6, 3, 14, 7, 34, 17, 84, 42, 21, 104, 52, 26, 13, 64, 32, 16, 8, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1

Offset

1,1

Links

Table of n, a(n) for n=1..90.

Formula

a(1) = 50, a(n+1) = a(n)/2 if a(n) even, otherwise 5*a(n) - 1.

Mathematica

NestList[If[EvenQ[#], #/2, 5# - 1] &, 50, 100] (* Alonso del Arte, Aug 12 2016 *)

Prog

(Magma) [n eq 1 select 50 else IsOdd(Self(n-1)) select 5*Self(n-1)-1 else Self(n-1) div 2: n in [1..80]]; // Vincenzo Librandi, Aug 21 2016

Crossrefs

Cf. A008880.

Sequence in context: A072460 A248128 A033370 * A033980 A342903 A207149

Adjacent sequences: A090688 A090689 A090690 * A090692 A090693 A090694

Keyword

nonn,easy

Author

Daniil Khanin (daniil(AT)ispms.tsc.ru), Feb 06 2004

Extensions

More terms from Ray Chandler, Feb 08 2004

New definition by Alonso del Arte, Aug 12 2016

Status

approved