A014693 - OEIS

A014693

In sequence of prime numbers add 1 to first number, 2 to 3rd number, 3 to 5th number, ... then subtract 1 from 2nd number, 2 from 4th number, 3 from 6th number and so on.

3, 2, 7, 5, 14, 10, 21, 15, 28, 24, 37, 31, 48, 36, 55, 45, 68, 52, 77, 61, 84, 68, 95, 77, 110, 88, 117, 93, 124, 98, 143, 115, 154, 122, 167, 133, 176, 144, 187, 153, 200, 160, 213, 171, 220, 176, 235, 199, 252, 204, 259, 213, 268, 224, 285, 235, 298, 242, 307

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

OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

PROG

(PARI) a(n) = if (n % 2, prime(n) + ceil(n/2), prime(n) - ceil(n/2)); \\ Michel Marcus, Nov 18 2018

(Magma) [IsOdd(n) select (NthPrime(n)+Ceiling(n/2)) else (NthPrime(n)- Ceiling(n/2)): n in [1..70]]; // Vincenzo Librandi, Nov 18 2018

CROSSREFS

Sequence in context: A292204 A292203 A295642 * A318783 A253564 A232751

Adjacent sequences: A014690 A014691 A014692 * A014694 A014695 A014696

KEYWORD