A079079 a(n) = (prime(n)+1)*(prime(n+1)+1)/4.

3, 6, 12, 24, 42, 63, 90, 120, 180, 240, 304, 399, 462, 528, 648, 810, 930, 1054, 1224, 1332, 1480, 1680, 1890, 2205, 2499, 2652, 2808, 2970, 3135, 3648, 4224, 4554, 4830, 5250, 5700, 6004, 6478, 6888, 7308, 7830, 8190, 8736, 9312, 9603, 9900, 10600

Offset

1,1

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Mathematica

Table[(Prime[n] + 1)*(Prime[n + 1] + 1)/4, {n, 1, 50}] (* G. C. Greubel, Apr 25 2017 *)

Prog

(PARI) a(n)=(prime(n)+1)*(prime(n+1)+1)/4 \\ Charles R Greathouse IV, Aug 21 2011
(Haskell)
a079079 n = a079079_list !! (n-1)
a079079_list = map (`div` 4) $
               zipWith (*) a008864_list $ tail a008864_list
-- Reinhard Zumkeller, Oct 08 2012
(Python)
from sympy import prime
def a(n): return (prime(n) + 1)*(prime(n + 1) + 1)/4 # Indranil Ghosh, Apr 26 2017

Crossrefs

Cf. A079080, A079081, A079082, A079095, smallest, greatest factor: A079083, A079084, number of factors: A079085, A079086, A079087, number, sum of divisors: A079088, A079089, sum of prime factors: A079090, A079091, Euler's totient: A079092, squarefree kernel: A079093, arithmetic derivative: A079094.

Sequence in context: A363692 A330132 A039695 * A283839 A336758 A364497

Adjacent sequences: A079076 A079077 A079078 * A079080 A079081 A079082

Keyword

nonn

Author

Reinhard Zumkeller, Dec 22 2002

Status

approved