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.

A253682 Prime sums of three distinct Mersenne primes (A000668).

Original entry on oeis.org

41, 137, 2147483777, 162259895799233006081715459850241
Offset: 1

Views

Author

G. L. Honaker, Jr., Jan 08 2015

Keywords

Comments

a(1) has the exponents of the three distinct Mersenne primes of 1, 2 and 3; a(2) the exponents are 1, 2 and 4, a(3) the exponents are 1, 4 and 8 and a(4) the exponents are 1, 10 and 11. - Robert G. Wilson v, Jan 08 2015
a(5) > 10^30000, if it exists. - Jinyuan Wang, Jul 26 2021

Examples

			a(3) = 2147483777 because 2147483777 = (2^2-1) + (2^7-1) + (2^31-1).
		

Crossrefs

Programs

  • Mathematica
    exp={* the first 34 terms in A000043 *}; Do[ s = 2^exp[[p]] + 2^exp[[q]] + 2^exp[[r]] - 3; If[ PrimeQ@ s, Print[{p, q, r, s}]], {r, 3, 34}, {q, 2, r - 1}, {p, q - 1}] (* Robert G. Wilson v, Jan 08 2015 *)