A350606 a(n) is the number of elements in row n of A350605.

1, 3, 7, 15, 30, 60, 119, 237, 472, 940, 1874, 3740, 7469, 14918, 29805, 59561, 119043, 237966, 475750, 951213, 1901981, 3803271, 7605468, 15209251, 30415896, 60827703, 121648985, 243287862, 486559789, 973094453, 1946149237

Offset

1,2

Comments

It would be nice to have a formula.

Links

Table of n, a(n) for n=1..31.

Prog

(Python)
from itertools import chain, islice
def A350606_gen(): # generator of terms
    s = {1}
    while True:
        yield len(s)
        s = set(chain.from_iterable((x, 2*x+1, 3*x+1) for x in s))
A350606_list = list(islice(A350606_gen(), 20)) # Chai Wah Wu, Jan 12 2022

Crossrefs

Cf. A350605.

Sequence in context: A023610 A062544 A120411 * A224520 A291754 A336685

Adjacent sequences: A350603 A350604 A350605 * A350607 A350608 A350609

Keyword

nonn,more

Author

N. J. A. Sloane, Jan 12 2022

Extensions

a(14)-a(31) from Chai Wah Wu, Jan 12 2022

Status

approved