A085681 Integers of the form 2^n*p where p is a prime > 2^n.

6, 10, 14, 20, 22, 26, 28, 34, 38, 44, 46, 52, 58, 62, 68, 74, 76, 82, 86, 88, 92, 94, 104, 106, 116, 118, 122, 124, 134, 136, 142, 146, 148, 152, 158, 164, 166, 172, 178, 184, 188, 194, 202, 206, 212, 214, 218, 226, 232, 236, 244, 248, 254, 262, 268, 272, 274

Offset

1,1

Comments

Reason for considering sequence: if even numbers are equally distributed mod p>2, then the number of integers of this set up to a certain number would tend to be equal to the number of primes. Therefore it could be useful if we know the primes up to a given number x to estimate the primes to 2x

Links

Table of n, a(n) for n=1..57.

Example

For instance 2*3, 2*5, 2*7, ..., 4*5, 4*7, 4*11, ..., 8*11, 8*13, ..., 16*17, 16*19, ...

Mathematica

f[n_] := Table[2^n*Prime[i], {i, PrimePi[2^n] + 1, 35}]; Take[ Sort[ Flatten[ Table[ f[n], {n, 1, 4}]]], 57]

Crossrefs

Sequence in context: A006617 A246803 A140695 * A315199 A315200 A315201

Adjacent sequences: A085678 A085679 A085680 * A085682 A085683 A085684

Keyword

nonn

Author

Alberto Zelaya (azelaya(AT)xtra.co.nz), Jul 17 2003

Extensions

Edited and extended by Robert G. Wilson v, Jul 19 2003

Status

approved