A100566 2*a(n) = prime(prime(n)) + prime(prime(2n)).

11, 26, 42, 70, 99, 125, 154, 183, 231, 264, 309, 363, 389, 414, 490, 537, 580, 649, 692, 727, 786, 824, 935, 978, 1023, 1080, 1128, 1170, 1220, 1311, 1401, 1436, 1533, 1605, 1647, 1734, 1807, 1855, 1917, 1986, 2053, 2131, 2200, 2250, 2312, 2407, 2501, 2583

Offset

2,1

Links

Table of n, a(n) for n=2..49.

Formula

a(n) = (A006450(n)+A006450(2n))/2.

Mathematica

A=Floor[Log[2]*n/Log[2]] B=Floor[2*Log[2]*n/Log[2]] f[n_]:=(Prime[Prime[A]]+Prime[Prime[B]])/2 digits=200 a=Table[f[n], {n, 2, digits}]

Crossrefs

Cf. A100567.

Sequence in context: A003345 A047722 A161451 * A101969 A139576 A166137

Adjacent sequences: A100563 A100564 A100565 * A100567 A100568 A100569

Keyword

nonn

Author

Roger L. Bagula, Nov 28 2004

Status

approved