cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A066886 Sum of the elements in any transversal of a prime(n) X prime(n) array containing the numbers from 1 to prime(n)^2 in standard order.

Original entry on oeis.org

5, 15, 65, 175, 671, 1105, 2465, 3439, 6095, 12209, 14911, 25345, 34481, 39775, 51935, 74465, 102719, 113521, 150415, 178991, 194545, 246559, 285935, 352529, 456385, 515201, 546415, 612575, 647569, 721505, 1024255, 1124111, 1285745
Offset: 1

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Author

Enoch Haga, Jan 22 2002

Keywords

Comments

a(n) is the sum of the primes in a prime(n) X prime(n) example of Haga's conjecture (see link below).

Crossrefs

Programs

  • Maple
    map(t -> t*(t^2+1)/2, [seq(ithprime(i),i=1..100)]); # Robert Israel, Apr 04 2018
  • Mathematica
    a[n_] := Prime[n] (Prime[n]^2 + 1)/2; Table[a[n], {n, 50}]
  • PARI
    apply(x->(x*(x^2+1)/2), primes(100)) \\ Michel Marcus, Apr 04 2018

Formula

a(n) = prime(n)*(prime(n)^2+1)/2, where prime(n) is the n-th prime.
a(n) = A006003(prime(n)). - Michel Marcus, Apr 04 2018
a(n) = A006254(n-1)^4 - A005097(n-1)^4, for n>1. - Dimitris Valianatos, Apr 10 2018

Extensions

Edited by Dean Hickerson, Jun 08 2002