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.

A276459 Nested radical expansion of Pi: Pi = sqrt(a(1) + sqrt(a(2) + sqrt(a(3) + sqrt(a(4) + ...)))), with a(1) = 7 and 2 <= a(n) <= 6 for n>1.

Original entry on oeis.org

7, 6, 2, 6, 6, 5, 5, 2, 4, 6, 3, 4, 2, 4, 6, 3, 6, 3, 3, 5, 4, 3, 6, 3, 3, 3, 4, 3, 6, 6, 4, 3, 3, 4, 5, 5, 2, 6, 2, 5, 4, 3, 4, 6, 6, 2, 3, 5, 2, 3, 5, 4, 2, 3, 2, 4, 2, 6, 4, 6, 3, 3, 4, 3, 4, 6, 3, 4, 6, 5, 2, 2, 2, 3, 4, 5, 5, 5, 2, 4, 3, 6, 4, 3, 6, 3, 2, 6, 2, 4, 5, 6, 2, 3, 2, 5, 2, 3, 2, 3, 3, 5, 4, 4, 6, 4, 2, 4, 5, 4, 6, 5, 3
Offset: 1

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Author

Yuriy Sibirmovsky, Sep 03 2016

Keywords

Comments

Similar to Bolyai expansion. Uses the fact that for 0

Examples

			Pi^2=7+2+p1, thus a(1)=7;
(2+p1)^2=6+2+p2, thus a(2)=6;
(2+p2)^2=2+2+p3, thus a(3)=2; ... 0<pn<1.
		

Crossrefs

Cf. A000796 (digits), A001203 (continued fraction).

Programs

  • Mathematica
    Nm=100;
    A=Table[1,{j,1,Nm}];
    V=Table[1,{j,1,Nm}];
    P=Pi;
    p0=P;
    Do[p1=Floor[p0^2]-2;
    A[[j]]=p1;
    p0=N[2+p0^2-Floor[p0^2],300],{j,1,Nm}];
    Do[v0=Sqrt[A[[n]]];
    Do[v1=A[[n-j]]+v0;
    v0=Sqrt[v1],{j,1,n-1}];
    V[[n]]=v0,{n,1,Nm}];
    A