A109763 Primes repeated.

2, 2, 3, 3, 5, 5, 7, 7, 11, 11, 13, 13, 17, 17, 19, 19, 23, 23, 29, 29, 31, 31, 37, 37, 41, 41, 43, 43, 47, 47, 53, 53, 59, 59, 61, 61, 67, 67, 71, 71, 73, 73, 79, 79, 83, 83, 89, 89, 97, 97, 101, 101, 103, 103, 107, 107, 109, 109, 113, 113, 127, 127, 131, 131

Offset

1,1

Links

Table of n, a(n) for n=1..64.

Formula

a(n) = A000040(ceiling(n/2)). - Jon Perry, Oct 29 2014

Mathematica

With[{prs=Prime[Range[40]]}, Riffle[prs, prs]] (* Harvey P. Dale, Oct 10 2014 *)

Crossrefs

Sequence in context: A239880 A240862 A177716 * A321523 A226748 A119620

Adjacent sequences: A109760 A109761 A109762 * A109764 A109765 A109766

Keyword

easy,nonn

Author

Giovanni Teofilatto, Aug 13 2005

Status

approved