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.

A339412 a(n) = floor(x(n)) where x(n) = (frac(x(n-1))+1)*floor(x(n-1)) and x(1) = Pi.

Original entry on oeis.org

3, 3, 4, 5, 5, 7, 10, 10, 13, 17, 31, 35, 67, 123, 223, 305, 414, 822, 1550, 2224, 3273, 4560, 7804, 14372, 15493, 20080, 40039, 44226, 71916, 130773, 183760, 316165, 613602, 1066559, 1138668, 1202427, 2022144, 2251837, 2477524, 4479491, 7192184, 11256849
Offset: 1

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Author

Michael Turniansky, Dec 03 2020

Keywords

Comments

Inspired by A249270.

Crossrefs

Programs

  • Maple
    b:= proc(n) option remember; `if`(n=1, Pi,
          (f-> (frac(f)+1)*floor(f))(b(n-1)))
        end:
    a:= n-> floor(b(n)):
    seq(a(n), n=1..50);  # Alois P. Heinz, Dec 03 2020
  • Mathematica
    Block[{a = {Pi}, $MaxExtraPrecision = 10^3}, Do[AppendTo[a, (FractionalPart[#] + 1) Floor[#]] &@ a[[-1]], 41]; Floor /@ a] (* Michael De Vlieger, Dec 04 2020 *)
  • NARS2000
    {(⌊{(⌊⍵)×1+1|⍵}⍣⍵)○1x}¨0,⍳100
    
  • PARI
    lista(nn) = {localprec(500); my(vx = vector(nn)); vx[1] = Pi; for (n=2, nn, vx[n] = (frac(vx[n-1])+1)*floor(vx[n-1]);); apply(floor, vx);} \\ Michel Marcus, Dec 03 2020