A088593 a(0)=18; a(n+1) = largest odd factor of 3*a(n)+1; stop when a(n)=1.

18, 55, 83, 125, 47, 71, 107, 161, 121, 91, 137, 103, 155, 233, 175, 263, 395, 593, 445, 167, 251, 377, 283, 425, 319, 479, 719, 1079, 1619, 2429, 911, 1367, 2051, 3077, 577, 433, 325, 61, 23, 35, 53, 5, 1

Offset

0,1

Comments

Similar to a Collatz sequence.

Links

Table of n, a(n) for n=0..42.

Formula

a(n+1) = A000265(3*a(n)+1). - Michel Marcus, Aug 23 2022

Example

a(4)=47 because (a(3)*3+1)/2^3 = 47.

Prog

(PARI) f(n) = n >> valuation(n, 2); \\ A000265
lista(nn) = my(list=List(), x = 18, i=0); while (1, listput(list, x); x = f(3*x+1); i++; if (i>100, break)); Vec(list); \\ Michel Marcus, Aug 23 2022

Crossrefs

Cf. A000265.

Sequence in context: A069973 A272138 A041630 * A033571 A041632 A086540

Adjacent sequences: A088590 A088591 A088592 * A088594 A088595 A088596

Keyword

easy,nonn,fini,full

Author

Mitch Cervinka (puritan(AT)planetkc.com), Nov 20 2003

Extensions

Edited by Don Reble, Nov 08 2005

Corrected by Doug Unger, Aug 26 2022

Status

approved