A079415 a(n) = floor(prime(n)/n) * ceiling(prime(n)/n) / 2.

2, 1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 15, 10, 10, 10, 15, 15, 15, 15, 15, 15, 15

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..10000

Mathematica

fc[n_]:=Module[{c=Prime[n]/n}, (Floor[c]Ceiling[c])/2]; Array[fc, 80] (* Harvey P. Dale, May 20 2015 *)

Prog

(PARI) vector(80, n, floor(prime(n)/n)*ceil(prime(n)/n)/2) \\ G. C. Greubel, Jan 19 2019
(Magma) [Floor(NthPrime(n)/n)*Ceiling(NthPrime(n)/n)/2: n in [1..80]]; // G. C. Greubel, Jan 19 2019
(Sage) [floor(nth_prime(n)/n)*ceil(nth_prime(n)/n)/2 for n in (1..80)] # G. C. Greubel, Jan 19 2019

Crossrefs

Cf. A038605, A079416, A000040.

Sequence in context: A227543 A366920 A344678 * A126347 A309240 A057001

Adjacent sequences: A079412 A079413 A079414 * A079416 A079417 A079418

Keyword

nonn

Author

Reinhard Zumkeller, Jan 07 2003

Status

approved