A157644 Indices of 3's in A090822.

9, 18, 28, 37, 41, 45, 46, 56, 65, 75, 84, 88, 92, 93, 97, 107, 116, 126, 135, 139, 143, 144, 154, 163, 173, 182, 186, 190, 191, 195, 199, 203, 204, 208, 212, 216, 217, 218, 219, 229, 238, 248, 257, 261, 265, 266, 276, 285, 295, 304, 308, 312, 313, 317, 327, 336, 346, 355

Offset

1,1

Comments

There is a group a(i+39) = a(i)+220 for i=1,..,39, then a group a(i+39)=a(i)+220 for i=40,...,78; these correlations become irregular later in the sequence.

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Mathematica

Clear[a]; reversed = {a[2] = 1, a[1] = 1}; blocs[len_] := Module[{bloc1, par, pos}, bloc1 = Take[reversed, len]; par = Partition[reversed, len]; pos = Position[par, bloc_ /; bloc != bloc1, 1, 1]; If[pos == {}, Length[par], pos[[1, 1]] - 1]]; a[n_] := a[n] = Module[{an}, an = Table[{blocs[len], len}, {len, 1, Quotient[n - 1, 2]}] // Sort // Last // First; PrependTo[reversed, an]; an]; Position[Table[a[n], {n, 1, 355}], 3] // Flatten (* Jean-François Alcover, Mar 25 2013 *)

Crossrefs

Cf. A157334, A107223, A157645.

Sequence in context: A115552 A043322 A071121 * A107223 A194152 A044433

Adjacent sequences: A157641 A157642 A157643 * A157645 A157646 A157647

Keyword

nonn

Author

Paul Curtz, Mar 03 2009

Extensions

Extended by R. J. Mathar, Mar 15 2009

Status

approved