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.

Showing 1-2 of 2 results.

A078464 Erroneous version of A177454.

Original entry on oeis.org

2, 6, 50, 64130, 800046, 137270954, 1860277042, 357975249026, 1036802293087622, 15013817846943906, 47192717955016924590, 10360599532897359064118, 154361699651715243559786
Offset: 1

Views

Author

Benoit Cloitre, Jan 01 2003

Keywords

Extensions

Missing a(4) pointed out by Gary Detlefs, Feb 27 2013

A060842 a(n) = (binomial(2*p,p)-2)/p^2 where p = prime(n).

Original entry on oeis.org

1, 2, 10, 70, 5830, 61542, 8074762, 97909318, 15564141262, 35751803209918, 484316704740126, 1275478863649106070, 252697549582862416198, 3589806968644540547902, 735944382229592689247902, 2233009988826006212007799102, 6997040996166222103946741339278, 103007775714125517422789307317230
Offset: 1

Views

Author

Benoit Cloitre, Feb 13 2003

Keywords

Programs

  • Mathematica
    Table[(Binomial[2p,p]-2)/p^2,{p,Prime[Range[20]]}] (* Harvey P. Dale, Mar 05 2023 *)
  • PARI
    a(n) = { my(p=prime(n)); (binomial(2*p, p) - 2)/p^2 } \\ Harry J. Smith, Jul 19 2009

Formula

a(n) = A177454(n)/A000040(n). - R. J. Mathar, Jan 09 2017
Showing 1-2 of 2 results.