A085181 Inverse permutation to A085180.
1, 2, 3, 5, 4, 6, 9, 10, 14, 8, 15, 20, 13, 7, 21, 27, 28, 35, 19, 36, 44, 45, 54, 26, 55, 65, 34, 12, 66
Offset: 1
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.
From _John M. Campbell_, Sep 07 2018: (Start) Letting m = 5, as above let (T(1) < T(2) < ... < T(42)) denote the lexicographic sequence of Young tableaux of shape (2, 2, 2, 2, 2). In this case, the sequence (f(T(1), T(43 - i)) - f(T(42 - i), T(43 - i)), i=1..41) is equal to (0, 1, 0, 0, 2, 0, 1, 0, 0, 2, 0, 0, 0, 3, 0, 1, 0, 0, 2, 0, 1, 0, 0, 2, 0, 0, 0, 3, 0, 1, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 0). Removing the zeroes from this tuple, we obtain (1, 2, 1, 2, 3, 1, 2, 1, 2, 3, 1, 2, 3), which gives us the first 13 = A000108(m - 1) - 1 terms in this sequence. For example, the first term in the preceding tuple is 0 since T(1) and T(42) are respectively [ 5 10] [ 9 10] [ 4 9 ] [ 7 8 ] [ 3 8 ] [ 5 6 ] [ 2 7 ] [ 3 4 ] [ 1 6 ] [ 1 2 ] and T(41) is equal to [ 9 10] [ 7 8 ] [ 5 6 ] [ 2 4 ] [ 1 3 ] so that the first letter of disagreement between T(1) and T(42) is 2, and that between T(41) and T(42) is also 2. (End)
Nest[ Flatten[ # /. a_Integer -> Range[a + 1]] &, {1}, 6] (* Robert G. Wilson v, Jan 24 2006 *)
a(n)=local(v,w); if(n<1,0,v=[1]; while(#v
PositionIndex[Nest[Flatten[Map[Range[#+1] &, #]] &, {1}, 6]][[1]] (* Paolo Xausa, Mar 04 2024 *)
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