A141619 a(n) = 3*(n+1)/2 if n is odd, a(n) = prime(n/2) if n is even.

3, 2, 6, 3, 9, 5, 12, 7, 15, 11, 18, 13, 21, 17, 24, 19, 27, 23, 30, 29, 33, 31, 36, 37, 39, 41, 42, 43, 45, 47, 48, 53, 51, 59, 54, 61, 57, 67, 60, 71, 63, 73, 66, 79, 69, 83, 72, 89, 75, 97, 78, 101, 81, 103, 84, 107, 87, 109, 90, 113, 93, 127, 96, 131, 99, 137, 102, 139, 105, 149

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Mathematica

f[n_] := If[OddQ@n, 3 (n + 1)/2, Prime[n/2]]; Array[f, 70] (* Robert G. Wilson v, Sep 22 2008 *)

Prog

(PARI) a(n) = if (n % 2, 3*(n+1)/2, prime(n/2)); \\ Michel Marcus, Feb 21 2017

Crossrefs

Sequence in context: A341516 A060992 A064455 * A270143 A363278 A065021

Adjacent sequences: A141616 A141617 A141618 * A141620 A141621 A141622

Keyword

nonn

Author

Marina (kiev.marina(AT)gmail.com), Aug 23 2008

Extensions

Definition found by Alexander R. Povolotsky, Aug 26 2008

More terms based on Alexander R. Povolotsky's definition from N. J. A. Sloane, Aug 27 2008

Status

approved