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A350606
a(n) is the number of elements in row n of A350605.
1
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.
Conjecture: a(n) is approximately = k*2^(n-5) for n>4. - Bill McEachen, Jul 30 2024
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 A373089 A291754
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