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.

A058077 Binomial coefficients formed from consecutive primes: a(n) = binomial( prime(n+1), prime(n) ).

Original entry on oeis.org

3, 10, 21, 330, 78, 2380, 171, 8855, 475020, 465, 2324784, 101270, 903, 178365, 22957480, 45057474, 1830, 99795696, 971635, 2628, 277962685, 1837620, 581106988, 144520208820, 4082925, 5253, 5160610, 5886, 6438740
Offset: 1

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Author

Labos Elemer, Nov 13 2000

Keywords

Comments

Conjecture: for each value of n > 1, if a(n+1) has the same number of digits as a(n) and a(n+1) > a(n), then prime(n+2) - prime(n+1) = prime(n+1) - prime(n). This conjecture has been verified for all n < 3*10^7. - Ahmad J. Masad, Oct 08 2019

Examples

			n=6: a(6) = C(p(7),p(6)) = C(17,13) = 57120/24 = 2380.
		

Crossrefs

Programs

  • Mathematica
    Table[Binomial[Prime[n+1],Prime[n]],{n,1,20}] (* Vaclav Kotesovec, Nov 13 2014 *)

Formula

a(n) = binomial(A000040(n+1), A001223(n)).

Extensions

Offset corrected by Vaclav Kotesovec, Nov 13 2014