The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A174084 Number of permutations of length n with no consecutive triples i,...i+r,...i+2r for all r, and for all equal spacings d. 3
 21, 94, 544, 3509, 26799, 223123 (list; graph; refs; listen; history; text; internal format)
 OFFSET 4,1 COMMENTS Here we count both the sequence 1,2,3 (r=1) as a progression in 1,2,3,0,4,5, (note d=1) and in 1,0,2,4,3,5 (here, d=2). LINKS Table of n, a(n) for n=4..9. EXAMPLE For n=4 there are 4!-a(4)=3 with some progression. These are (0,1,2,3), (1,2,3,0), and (3,0,1,2). Here for all the progressions, r=1 and d=1, hence this term is the same as a(4) in A002628. CROSSREFS Cf. A002628, A174080, A174085, A174086, A174087. Sequence in context: A219423 A123213 A296822 * A193218 A220157 A264239 Adjacent sequences: A174081 A174082 A174083 * A174085 A174086 A174087 KEYWORD nonn AUTHOR Isaac Lambert, Apr 20 2010 STATUS approved

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

Last modified November 28 06:02 EST 2023. Contains 367394 sequences. (Running on oeis4.)