A163587 Primes of the form floor(2 * (k+j) * log(2*(k+j))), 0 <= j <= k.

5, 23, 29, 59, 307, 383, 449, 691, 727, 739, 751, 787, 947, 971, 1009, 1021, 1097, 1237, 1289, 1367, 1511, 1657, 1697, 1913, 2063, 2243, 2579, 2593, 2621, 2749, 2777, 2791, 2963, 3049, 3121, 3251, 3499, 3617, 3631, 3779, 3793, 3823, 4001, 4691, 4721, 4919, 5087

Offset

1,1

Comments

Suggested by Ramanujan's: 2*n*log(2*n) < R(n) < 4*n*log(4*n).

The result is not A104272, but seems to be distantly related.

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Jonathan Sondow, Ramanujan primes and Bertrand's postulate, Amer. Math. Monthly, Vol. 116, No. 7 (2009), 630-635; arXiv preprint, arXiv:0907.5232 [math.NT], 2009-2010.

Mathematica

a[n_] = Floor[2*n*Log[2*n]]; Table[Table[If[PrimeQ[a[n + m]], a[n + m], {}], {m, 0, 2*n}], {n, 1, 100}]; Union[Flatten[%]]

Crossrefs

Cf. A104272.

Sequence in context: A067367 A140386 A105880 * A038922 A019367 A065867

Adjacent sequences: A163584 A163585 A163586 * A163588 A163589 A163590

Keyword

nonn

Author

Roger L. Bagula, Jul 31 2009

Extensions

Revised by Sean A. Irvine, Feb 01 2026

Status

approved