Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A138403
a(n) = p^3*(p-1), where p = prime(n).
5
8, 54, 500, 2058, 13310, 26364, 78608, 123462, 267674, 682892, 893730, 1823508, 2756840, 3339294, 4775858, 7741604, 11911982, 13618860, 19850358, 25053770, 28009224, 38457042, 46886534, 62037272, 87616608, 103030100, 111458154
OFFSET
1,1
FORMULA
a(n) = A000010(prime(n)^4). - R. J. Mathar, Oct 15 2017
From Amiram Eldar, Nov 22 2022: (Start)
a(n) = prime(n)^4 - prime(n)^3 = A030514(n) - A030078(n).
Product_{n>=1} (1 - 1/a(n)) = A065415. (End)
MATHEMATICA
a = {}; Do[p = Prime[n]; AppendTo[a, p^4 - p^3], {n, 1, 50}]; a
PROG
(PARI) forprime(p=2, 1e3, print1(p^4-p^3", ")) \\ Charles R Greathouse IV, Jun 16 2011
(Magma) [NthPrime((n))^4 - NthPrime((n))^3: n in [1..40] ]; // Vincenzo Librandi, Jun 17 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Artur Jasinski, Mar 19 2008
STATUS
approved