A019462 Add 1, multiply by 1, add 2, multiply by 2, etc., start with 3.

3, 4, 4, 6, 12, 15, 45, 49, 196, 201, 1005, 1011, 6066, 6073, 42511, 42519, 340152, 340161, 3061449, 3061459, 30614590, 30614601, 336760611, 336760623, 4041127476, 4041127489, 52534657357, 52534657371, 735485203194, 735485203209, 11032278048135, 11032278048151

Offset

0,1

Links

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

Nick Hobson, Python program for this sequence

Mathematica

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

Prog

(PARI) A019462(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. A019461 (same, but start with 0), A019463 (start with 1), A019460 (start with 2), A082448 (start with 4).

Cf. A082458, A019464 .. A019466 (similar, but first multiply, then add).

Sequence in context: A378435 A325973 A363289 * A078071 A359789 A084138

Adjacent sequences: A019459 A019460 A019461 * A019463 A019464 A019465

Keyword

nonn

Author

N. J. A. Sloane

Extensions

Edited by M. F. Hasler, Feb 25 2018

Status

approved