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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A074298 First occurrence of an 'average' valued sequence of length 2n in the Kolakoski sequence (A000002).

Original entry on oeis.org

1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 9, 4, 4, 3, 1, 4, 3, 1, 1, 9, 4, 4, 3, 1, 1, 3, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 3, 1, 1, 1, 1, 3, 1, 1, 4, 3
Offset: 1

Views

Author

Jon Perry, Sep 21 2002

Keywords

Comments

a(n) is the least k such that K(k) + K(k+1) + ... + K(k + 2*n - 1) = 3*n, where K(m) = A000002(m).

Examples

			a[1]=1, as A000002 begins 1,2 (sum 3) a[2]=1, as A000002 begins 1,2,2,1 (sum 6) a[3]=1, as A000002 begins 1,2,2,1,1,2 (sum 9).
		

Crossrefs

Programs

  • Mathematica
    nmax = 90; a2 = {1, 2, 2}; For[n = 3, n <= 2*nmax, n++, For[i = 1, i <= a2[[n]], i++, AppendTo[a2, 1 + Mod[n - 1, 2]]]]; a[n_] := For[k = 1, True, k++, If[Plus @@ a2[[k ;; k + 2*n - 1]] == 3*n, Return[k]]]; Table[a[n], {n, 1, nmax}] (* Jean-François Alcover, Sep 25 2012 *)

Extensions

Offset corrected by Nathaniel Johnston, May 02 2011

A074297 Position of the first occurrence of n consecutive terms with the largest possible sum in the Kolakoski sequence (A000002).

Original entry on oeis.org

2, 2, 1, 6, 8, 6, 6, 2, 1, 2, 2, 1, 33, 53, 33, 6, 50, 2, 72, 74, 72, 72, 296, 295, 33, 293, 74, 324, 35, 296, 33, 35, 33, 33, 32, 2261, 30, 53, 52, 53, 53, 52, 276, 50, 33, 273, 296, 53, 296, 2883, 330, 33, 296, 295, 296, 296, 295, 33, 35, 33, 33, 32, 324, 30, 278, 35, 276
Offset: 1

Views

Author

Jon Perry, Sep 21 2002

Keywords

Comments

The sequence of maximal sums begins 2, 4, 5, 7, 9, 10, 12, 13, 14, 16, 18, 19, 21, 23, 24, 25, 27, 28, 30, ...

Examples

			a(4)=6 because the Kolakoski sequence starting at position 6 is 2, 1, 2, 2 which sums to 7, which is the largest possible sum of 4 consecutive terms.
		

Crossrefs

Extensions

a(8)-a(15) from and edited by Nathaniel Johnston, May 02 2011
More terms from Hakan Icoz, Jan 01 2022
Showing 1-2 of 2 results.