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.

Showing 1-3 of 3 results.

A317361 a(n) is the index of the first occurrence of n in A317359.

Original entry on oeis.org

0, 1, 3, 6, 10, 39, 45, 25, 17, 527, 537, 55, 34, 134, 197, 309, 636, 66, 97, 555, 176, 2100, 285, 4247, 4499, 155, 8729, 591, 325, 1144, 1124, 4379, 211, 2331, 8534, 8573, 341, 609, 8482, 225, 1344, 9418, 4163, 34510, 357, 780, 239, 2122, 4583, 1204, 1544, 2683, 373, 253, 4211, 654, 45895, 33400, 2144
Offset: 0

Views

Author

Altug Alkan, Jul 26 2018

Keywords

Crossrefs

Cf. A317359.

A317369 a(0) = 0, a(1) = 1; for n >= 2, a(n) = freq(a(n-s(n)),n) where s = A000196 and freq(i, j) is the number of times i appears in the terms a(0) .. a(j-1).

Original entry on oeis.org

0, 1, 1, 2, 2, 2, 3, 3, 2, 2, 2, 6, 6, 6, 3, 3, 3, 3, 6, 6, 6, 6, 7, 7, 7, 7, 7, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 13, 13, 13, 13, 13, 13, 6, 6, 6, 6, 6, 6, 6, 20, 20, 20, 20, 20, 20, 20, 7, 7, 7, 7, 7, 7, 7, 7, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9
Offset: 0

Views

Author

Altug Alkan, Jul 26 2018

Keywords

Crossrefs

Programs

  • Mathematica
    Nest[Append[#1, Count[#1, #1[[-Floor@ Sqrt@ #2]] ]] & @@ {#, Length@ #} &, {0, 1}, 92] (* Michael De Vlieger, Jul 27 2018 *)

A317389 a(0) = 0, a(1) = a(2) = 1; for n >= 3, a(n) = freq(a(g(n)),n)*freq(a(n-g(n)),n) where g = A000195 and freq(i, j) is the number of times i appears in the terms a(0) .. a(j-1).

Original entry on oeis.org

0, 1, 1, 4, 2, 2, 4, 4, 6, 6, 4, 4, 10, 10, 4, 4, 14, 14, 4, 4, 18, 81, 81, 9, 18, 18, 9, 27, 27, 18, 18, 18, 54, 54, 54, 27, 27, 27, 45, 45, 45, 27, 27, 27, 72, 72, 72, 27, 27, 27, 99, 99, 99, 27, 27, 6, 6, 26, 26, 8, 8, 4, 4, 4, 4, 26, 26, 26, 26, 12, 12, 12, 12, 8, 8, 8, 8, 12, 12, 12, 12, 16, 16, 16, 16, 8, 8, 8, 8, 20, 20, 20
Offset: 0

Views

Author

Altug Alkan, Jul 27 2018

Keywords

Crossrefs

Cf. A317359.

Programs

  • Maple
    b:= proc() 0 end:
    a:= proc(n) option remember; local t;
          t:= `if`(n<3, n*(3-n)/2, b(a(ilog(n)))*b(a(n-ilog(n))));
          b(t):= b(t)+1; t
        end:
    seq(a(n), n=0..200);  # Alois P. Heinz, Jul 27 2018
  • Mathematica
    b[_] = 0;
    a[n_] := a[n] = Module[{t}, t = If[n<3, n(3-n)/2, b[a[Floor@Log[n]]] b[a[n - Floor@Log[n]]]]; b[t] = b[t]+1; t];
    a /@ Range[0, 200] (* Jean-François Alcover, Nov 27 2020, after Alois P. Heinz *)
Showing 1-3 of 3 results.