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.

A073557 Number of Fibonacci numbers F(k), k <= 10^n, whose initial digit is 1.

Original entry on oeis.org

3, 30, 301, 3011, 30103, 301031, 3010300, 30103001, 301029995, 3010299957, 30102999568
Offset: 1

Views

Author

Shyam Sunder Gupta, Aug 15 2002

Keywords

Examples

			a(2) = 30 because there are 30 Fibonacci numbers up to 10^2 whose initial digit is 1.
		

Crossrefs

Cf. A000045, A047855 (numbers of integers <= 10^n, whose initial digit is 1).

Programs

  • PARI
    default(realprecision, 10^4); m=log((1+sqrt(5))/2);
    lista(nn) = {my(d=log(10)/m, r=log(sqrt(5))/m, s=log(5-sqrt(5))/m, t=0, u=1); for(n=1, nn, u=10*u; while(sJinyuan Wang, Feb 21 2020

Formula

Limit_{n->infinity} a(n)/10^n = log(2), where the base is 10. - Robert Gerbicz, Sep 05 2002

Extensions

More terms from Robert Gerbicz, Sep 05 2002
a(9)-a(10) from Jinyuan Wang, Feb 21 2020
a(11) from Sean A. Irvine, Dec 04 2024