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

Author

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

Keywords

• nonn
• easy

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

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

Crossrefs

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

Programs

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);