This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A350606 #17 Jul 31 2024 11:42:03
%S A350606 1,3,7,15,30,60,119,237,472,940,1874,3740,7469,14918,29805,59561,
%T A350606 119043,237966,475750,951213,1901981,3803271,7605468,15209251,
%U A350606 30415896,60827703,121648985,243287862,486559789,973094453,1946149237
%N A350606 a(n) is the number of elements in row n of A350605.
%C A350606 It would be nice to have a formula.
%C A350606 Conjecture: a(n) is approximately = k*2^(n-5) for n>4. - _Bill McEachen_, Jul 30 2024
%o A350606 (Python)
%o A350606 from itertools import chain, islice
%o A350606 def A350606_gen(): # generator of terms
%o A350606 s = {1}
%o A350606 while True:
%o A350606 yield len(s)
%o A350606 s = set(chain.from_iterable((x,2*x+1,3*x+1) for x in s))
%o A350606 A350606_list = list(islice(A350606_gen(),20)) # _Chai Wah Wu_, Jan 12 2022
%Y A350606 Cf. A350605.
%K A350606 nonn,more
%O A350606 1,2
%A A350606 _N. J. A. Sloane_, Jan 12 2022
%E A350606 a(14)-a(31) from _Chai Wah Wu_, Jan 12 2022