A020934 - OEIS

A020934

Greatest k such that (k-th prime) < (4 times n-th prime).

4, 5, 8, 9, 14, 15, 19, 21, 24, 30, 30, 34, 38, 39, 42, 47, 51, 53, 56, 61, 61, 65, 67, 71, 76, 79, 80, 82, 84, 87, 96, 99, 101, 101, 108, 110, 114, 118, 121, 125, 127, 128, 135, 136, 138, 138, 146, 154, 155, 156, 158, 162, 162, 168, 172, 177, 180, 180, 185, 188

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..60.

MATHEMATICA

Table[PrimePi[NextPrime[4Prime[n], -1]], {n, 60}] (* Harvey P. Dale, Jan 15 2012 *)

CROSSREFS

Cf. A020900, A020901, A020934-A020940.

Sequence in context: A267489 A073320 A020668 * A094004 A228012 A067271

Adjacent sequences: A020931 A020932 A020933 * A020935 A020936 A020937

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

More terms from Henry Bottomley, Nov 13 2000

STATUS

approved