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.

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A050084 a(n) = floor(a(n-1)/3) if this is not among 0, a(1), ..., a(n-2); otherwise a(n) = 5*a(n-1).

Original entry on oeis.org

1, 5, 25, 8, 2, 10, 3, 15, 75, 375, 125, 41, 13, 4, 20, 6, 30, 150, 50, 16, 80, 26, 130, 43, 14, 70, 23, 7, 35, 11, 55, 18, 90, 450, 2250, 750, 250, 83, 27, 9, 45, 225, 1125, 5625, 1875, 625, 208, 69, 345, 115, 38, 12, 60, 300, 100, 33
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A050000 and references therein.

Programs

  • Mathematica
    Rest@Nest[Append[#, If[FreeQ[#, r = Quotient[#[[-1]], 3]], r, 5 #[[-1]]]] &, {0, 1}, 55] (* Ivan Neretin, Jul 31 2016 *)

A050104 a(n) = floor(a(n-1)/4) if this is not among 0, a(1), ..., a(n-2); otherwise a(n) = 3*a(n-1).

Original entry on oeis.org

1, 3, 9, 2, 6, 18, 4, 12, 36, 108, 27, 81, 20, 5, 15, 45, 11, 33, 8, 24, 72, 216, 54, 13, 39, 117, 29, 7, 21, 63, 189, 47, 141, 35, 105, 26, 78, 19, 57, 14, 42, 10, 30, 90, 22, 66, 16, 48, 144, 432, 1296, 324, 972, 243, 60, 180, 540, 135
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A050000 and references therein.

Programs

  • Mathematica
    Rest@Nest[Append[#, If[FreeQ[#, r = Quotient[#[[-1]], 4]], r, 3 #[[-1]]]] &, {0, 1}, 57] (* Ivan Neretin, Jul 31 2016 *)

A050124 a(1)=1; for n > 1, a(n) = floor(a(n-1)/5) if this is not among 0,a(1),...,a(n-1); otherwise a(n) = 2*a(n-1).

Original entry on oeis.org

1, 2, 4, 8, 16, 3, 6, 12, 24, 48, 9, 18, 36, 7, 14, 28, 5, 10, 20, 40, 80, 160, 32, 64, 128, 25, 50, 100, 200, 400, 800, 1600, 320, 640, 1280, 256, 51, 102, 204, 408, 81, 162, 324, 648, 129, 258, 516, 103, 206, 41, 82, 164, 328, 65
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A050000 and references therein.

Programs

  • Mathematica
    Rest@Nest[Append[#, If[FreeQ[#, r = Quotient[#[[-1]], 5]], r, 2 #[[-1]]]] &, {0, 1}, 53] (* Ivan Neretin, Jul 31 2016 *)

A050008 a(n) = floor(a(n-1)/2) if this is positive and not yet in the sequence, otherwise a(n) = 6*a(n-1).

Original entry on oeis.org

1, 6, 3, 18, 9, 4, 2, 12, 72, 36, 216, 108, 54, 27, 13, 78, 39, 19, 114, 57, 28, 14, 7, 42, 21, 10, 5, 30, 15, 90, 45, 22, 11, 66, 33, 16, 8, 48, 24, 144, 864, 432, 2592, 1296, 648, 324, 162, 81, 40, 20, 120, 60, 360, 180, 1080, 540, 270, 135
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A050000 and references therein.

Programs

  • Mathematica
    Rest@Nest[Append[#, If[FreeQ[#, r = Quotient[#[[-1]], 2]], r, 6 #[[-1]]]] &, {0, 1}, 57] (* Ivan Neretin, Jul 31 2016 *)
  • PARI
    first(n)=my(v=vector(n),t); v[1]=1; for(i=2,n, t=v[i-1]\2; if(t<2, v[i]=6*v[i-1]; next); for(j=1,i-1, if(v[j]==t, v[i]=6*v[i-1]; next(2))); v[i]=t); v \\ Charles R Greathouse IV, Jul 31 2016

A050016 a(n) = floor(a(n-1)/2) if this is positive and not yet in the sequence, otherwise a(n) = 9*a(n-1).

Original entry on oeis.org

1, 9, 4, 2, 18, 162, 81, 40, 20, 10, 5, 45, 22, 11, 99, 49, 24, 12, 6, 3, 27, 13, 117, 58, 29, 14, 7, 63, 31, 15, 135, 67, 33, 16, 8, 72, 36, 324, 2916, 1458, 729, 364, 182, 91, 819, 409, 204, 102, 51, 25, 225, 112, 56, 28, 252, 126, 1134
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A050000 and references therein.

Programs

  • Mathematica
    Rest@Nest[Append[#, If[FreeQ[#, r = Quotient[#[[-1]], 2]], r, 9 #[[-1]]]] &, {0, 1}, 56] (* Ivan Neretin, Jul 31 2016 *)
  • PARI
    first(n)=my(v=vector(n), t); v[1]=1; for(i=2, n, t=v[i-1]\2; if(t<2, v[i]=9*v[i-1]; next); for(j=1, i-1, if(v[j]==t, v[i]=9*v[i-1]; next(2))); v[i]=t); v \\ Charles R Greathouse IV, Jul 31 2016

A050020 a(n) = floor(a(n-1)/2) if this is positive and not yet in the sequence, otherwise a(n) = 10*a(n-1).

Original entry on oeis.org

1, 10, 5, 2, 20, 200, 100, 50, 25, 12, 6, 3, 30, 15, 7, 70, 35, 17, 8, 4, 40, 400, 4000, 2000, 1000, 500, 250, 125, 62, 31, 310, 155, 77, 38, 19, 9, 90, 45, 22, 11, 110, 55, 27, 13, 130, 65, 32, 16, 160, 80, 800, 8000, 80000, 40000, 20000
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A050000 and references therein.

Programs

  • Mathematica
    Rest@Nest[Append[#, If[MemberQ[#, c = Quotient[#[[-1]], 2]], 10*#[[-1]], c]] &, {0, 1}, 54] (* Ivan Neretin, Sep 06 2015 *)
  • PARI
    first(n)=my(v=vector(n), t); v[1]=1; for(i=2, n, t=v[i-1]\2; if(t<2, v[i]=10*v[i-1]; next); for(j=1, i-1, if(v[j]==t, v[i]=10*v[i-1]; next(2))); v[i]=t); v \\ Charles R Greathouse IV, Jul 31 2016

A050088 a(n) = floor(a(n-1)/3) if this is positive and not yet in the sequence, otherwise a(n) = 6*a(n-1).

Original entry on oeis.org

1, 6, 2, 12, 4, 24, 8, 48, 16, 5, 30, 10, 3, 18, 108, 36, 216, 72, 432, 144, 864, 288, 96, 32, 192, 64, 21, 7, 42, 14, 84, 28, 9, 54, 324, 1944, 648, 3888, 1296, 7776, 2592, 15552, 5184, 1728, 576, 3456, 1152, 384, 128, 768, 256, 85, 510
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A050000 and references therein.

Programs

  • Mathematica
    Rest@Nest[Append[#, If[FreeQ[#, r = Quotient[#[[-1]], 3]], r, 6 #[[-1]]]] &, {0, 1}, 52] (* Ivan Neretin, Jul 31 2016 *)
  • PARI
    first(n)=my(v=vector(n),t); v[1]=1; for(i=2,n, t=v[i-1]\3; if(t<2, v[i]=6*v[i-1]; next); for(j=1,i-1, if(v[j]==t, v[i]=6*v[i-1]; next(2))); v[i]=t); v \\ Charles R Greathouse IV, Jul 31 2016

A050092 a(n) = floor(a(n-1)/3) if this is positive and not yet in the sequence, otherwise a(n) = 7*a(n-1).

Original entry on oeis.org

1, 7, 2, 14, 4, 28, 9, 3, 21, 147, 49, 16, 5, 35, 11, 77, 25, 8, 56, 18, 6, 42, 294, 98, 32, 10, 70, 23, 161, 53, 17, 119, 39, 13, 91, 30, 210, 1470, 490, 163, 54, 378, 126, 882, 6174, 2058, 686, 228, 76, 532, 177, 59, 19, 133, 44, 308
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A050000 and references therein.

Programs

  • Mathematica
    Rest@Nest[Append[#, If[FreeQ[#, r = Quotient[#[[-1]], 3]], r, 7 #[[-1]]]] &, {0, 1}, 55] (* Ivan Neretin, Jul 31 2016 *)
  • PARI
    first(n)=my(v=vector(n),t); v[1]=1; for(i=2,n, t=v[i-1]\3; if(t<2, v[i]=7*v[i-1]; next); for(j=1,i-1, if(v[j]==t, v[i]=7*v[i-1]; next(2))); v[i]=t); v \\ Charles R Greathouse IV, Jul 31 2016

A050096 a(n) = floor(a(n-1)/3) if this is positive and not yet in the sequence, otherwise a(n) = 8*a(n-1).

Original entry on oeis.org

1, 8, 2, 16, 5, 40, 13, 4, 32, 10, 3, 24, 192, 64, 21, 7, 56, 18, 6, 48, 384, 128, 42, 14, 112, 37, 12, 96, 768, 256, 85, 28, 9, 72, 576, 4608, 1536, 512, 170, 1360, 453, 151, 50, 400, 133, 44, 352, 117, 39, 312, 104, 34, 11, 88, 29, 232
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A050000 and references therein.

Programs

  • Mathematica
    Rest@Nest[Append[#, If[FreeQ[#, r = Quotient[#[[-1]], 3]], r, 8 #[[-1]]]] &, {0, 1}, 55] (* Ivan Neretin, Jul 31 2016 *)
  • PARI
    first(n)=my(v=vector(n),t); v[1]=1; for(i=2,n, t=v[i-1]\3; if(t<2, v[i]=8*v[i-1]; next); for(j=1,i-1, if(v[j]==t, v[i]=8*v[i-1]; next(2))); v[i]=t); v \\ Charles R Greathouse IV, Jul 31 2016

A050100 a(n) = floor(a(n-1)/3) if this is positive and not yet in the sequence, otherwise a(n) = 10*a(n-1).

Original entry on oeis.org

1, 10, 3, 30, 300, 100, 33, 11, 110, 36, 12, 4, 40, 13, 130, 43, 14, 140, 46, 15, 5, 50, 16, 160, 53, 17, 170, 56, 18, 6, 2, 20, 200, 66, 22, 7, 70, 23, 230, 76, 25, 8, 80, 26, 260, 86, 28, 9, 90, 900, 9000, 3000, 1000, 333, 111, 37, 370
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A050000 and references therein.

Programs

  • Mathematica
    Rest@Nest[Append[#, If[FreeQ[#, r = Quotient[#[[-1]], 3]], r, 10 #[[-1]]]] &, {0, 1}, 56] (* Ivan Neretin, Jul 31 2016 *)
  • PARI
    first(n)=my(v=vector(n), t); v[1]=1; for(i=2, n, t=v[i-1]\3; if(t<2, v[i]=10*v[i-1]; next); for(j=1, i-1, if(v[j]==t, v[i]=10*v[i-1]; next(2))); v[i]=t); v \\ Charles R Greathouse IV, Jul 31 2016
Previous Showing 11-20 of 29 results. Next

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