A019466 - OEIS

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A019466

Multiply by 1, add 1, multiply by 2, add 2, etc.; start with 3.

3, 3, 4, 8, 10, 30, 33, 132, 136, 680, 685, 4110, 4116, 28812, 28819, 230552, 230560, 2075040, 2075049, 20750490, 20750500, 228255500, 228255511, 2739066132, 2739066144, 35607859872, 35607859885, 498510038390, 498510038404, 7477650576060, 7477650576075, 119642409217200

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,1

LINKS

Paolo Xausa, Table of n, a(n) for n = 0..800

MATHEMATICA

Module[{a = 3}, Join[{a}, Flatten[Array[{a *= #, a += #} &, 20]]]] (* Paolo Xausa, Oct 24 2024 *)

PROG

(PARI) A019466(n, a=3)={for(i=2, n+1, if(bittest(i, 0), a+=i\2, a*=i\2)); a} \\ M. F. Hasler, Feb 25 2018

CROSSREFS

Cf. A082458 (same, but start with 0), A019464 (start with 1), A019465 (start with 2).

Cf. A019460 .. A019463 & A082448 (similar, but first add, then multiply).