A080348 Costé prime expansion of Catalan's constant.

2, 2, 2, 5, 2, 5, 3, 7, 11, 5, 11, 7, 23, 13, 11, 3, 5, 2, 7, 5, 3, 7, 5, 13, 43, 43, 29, 17, 5, 2, 19, 11, 5, 3, 7, 5, 5, 3, 7, 7, 11, 3, 3, 7, 11, 2, 13, 7, 19, 13, 11, 11, 5, 3, 3, 3, 7, 7, 11, 3, 3, 7, 13, 37, 17, 7, 3, 7, 5, 5, 5, 2, 11, 5, 5, 5, 5, 2, 5, 5, 37, 7, 157, 53, 1361, 131, 107

Offset

0,1

Comments

For x in (0,1], define P(x) = min{p: p prime, 1/x < p}, Phi(x) = P(x)x - 1. Costé prime expansion of x(0) is sequence a(0), a(1), ... given by x(n) = Phi(x(n-1)) (n>0), a(n) = P(x(n)) (n >= 0).

Links

Table of n, a(n) for n=0..86.

A. Costé, Sur un système fibré lié à la suite des nombres premiers, Exper. Math., 11 (2002), 383-405.

Maple

Digits := 500: P := proc(x) local y; y := ceil(evalf(1/x)); if isprime(y) then y else nextprime(y); fi; end; F := proc(x) local y, i, t1; y := x; t1 := []; for i from 1 to 100 do p := P(y); t1 := [op(t1), p]; y := p*y-1; od; t1; end; F(Catalan);

Crossrefs

Cf. A079385, A079386, A079366, A079367, A079368.

Sequence in context: A368306 A368302 A368308 * A355198 A363924 A029662

Adjacent sequences: A080345 A080346 A080347 * A080349 A080350 A080351

Keyword

nonn,easy

Author

Mark Hudson (mrmarkhudson(AT)hotmail.com), Feb 17 2003

Status

approved