A162917 Numbers n which are not in A161983.

1, 2, 6, 7, 8, 9, 15, 16, 17, 18, 19, 20, 28, 29, 30, 31, 32, 33, 34, 35, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 120, 121, 122, 123, 124, 125, 126, 127, 128

Offset

1,2

Comments

They have a block structure: A000384(n) is followed by the next n integers.

Numbers k with the property that the largest Dyck path of the symmetric representation of sigma(k) has a central peak. (Cf. A237593.) - Omar E. Pol, Aug 28 2018

Union of nonzero terms of A000384 and A317303. - Omar E. Pol, Aug 29 2018

Links

Table of n, a(n) for n=1..65.

Formula

A000027 \ A161983.

Example

From Omar E. Pol, Aug 28 2018: (Start)
Also, written as an irregular triangle in which the row lengths are the positive even numbers, the sequence begins:
   1,  2;
   6,  7,  8,  9;
  15, 16, 17, 18, 19, 20;
  28, 29, 30, 31, 32, 33, 34, 35;
  45, 46, 47, 48, 49, 50, 51, 52, 53,  54;
  66, 67, 68, 69, 70, 71, 72, 73, 74,  75,  76,  77;
  91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104;
...
Row sums give A035328, n >= 1.
Column 1 gives A000384, n >= 1.
Column 2 gives A130883, n >= 1.
Right border gives the positive terms of A014107, also the odd-indexed terms of A000096.
(End)

Crossrefs

Complement of A161983.

Cf. A000096, A000384, A014107, A035328, A130883, A237593, A317303.

Sequence in context: A080780 A138168 A047279 * A250183 A260139 A118471

Adjacent sequences: A162914 A162915 A162916 * A162918 A162919 A162920

Keyword

nonn,tabf

Author

Juri-Stepan Gerasimov, Jul 17 2009

Extensions

119 removed by R. J. Mathar, Jul 19 2009

Status

approved