OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
EXAMPLE
If n=1, then (prime(1)^3-prime(1^3))/2 = (8-2)/2 = 6/2 = 3 = a(1).
If n=2, then (prime(2)^3-prime(2^3))/2 = (27-19)/2 = 8/2 = 4 = a(2).
If n=3, then (prime(3)^3-prime(3^3))/2 = (125-103)/2 = 22/2 = 11 = a(3).
If n=4, then (prime(4)^3-prime(4^3))/2 = (343-311)/2 = 32/2 = 16 = a(4).
If n=5, then (prime(5)^3-prime(5^3))/2 = (1331-691)/2 = 640/2 = 320 = a(5), etc.
MAPLE
A143680 := proc(n) option remember ; local p; (ithprime(n)^3-ithprime(n^3))/2 ; end: for n from 1 to 40 do printf("%d, ", A143680(n)) ; od: # R. J. Mathar, Nov 05 2008
MATHEMATICA
Table[(Prime[n]^3 - Prime[n^3]) / 2, {n, 50}] (* Vincenzo Librandi, Sep 15 2015 *)
PROG
(PARI) a(n) = (prime(n)^3 -prime(n^3))/2; \\ Michel Marcus, Sep 15 2015
(Magma) [(NthPrime(n)^3 -NthPrime(n^3))/2: n in [1..40]]; // Vincenzo Librandi, Sep 15 2015
(Sage) [(nth_prime(n)^3 - nth_prime(n^3))/2 for n in (1..40)] # G. C. Greubel, May 29 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Nov 01 2008
EXTENSIONS
More terms from R. J. Mathar, Nov 05 2008
STATUS
approved