The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A263788 Triangle read by rows: T(n,k) (n>=0, k>=0) is the number of permutations of n and convexity k. 0
 1, 1, 2, 4, 0, 0, 2, 6, 2, 0, 8, 4, 4, 8, 6, 2, 28, 20, 32, 12, 12, 8, 16, 6, 106, 80, 156, 120, 132, 48, 48, 8, 32, 16, 352, 396, 708, 696, 1044, 624, 684, 240, 240, 8, 58, 36, 1174, 1654, 3698, 3716, 6396, 5832, 6756, 3936, 4176, 1440, 1440, 8, 98, 80, 3752 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS The convexity of a permutation in one-line notation is the maximal value of twice an entry minus the sum of its neighbors. The row lengths are 2n-2 starting for n>=3. Row sums give A000142. LINKS FindStat - Combinatorial Statistic Finder, The convexity of a permutation. EXAMPLE Triangle begins:   1   1   2   4  0 0   2   6  2 0   8  4   4   8  6 2  28 20  32  12  12   8 16 6 106 80 156 120 132 48 48   ... CROSSREFS Cf. A000142. Sequence in context: A028586 A253179 A300723 * A292144 A300324 A298368 Adjacent sequences:  A263785 A263786 A263787 * A263789 A263790 A263791 KEYWORD nonn,tabf AUTHOR Christian Stump, Oct 26 2015 EXTENSIONS More terms from Alois P. Heinz, Oct 26 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 25 00:48 EDT 2020. Contains 337333 sequences. (Running on oeis4.)