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!)
 A293996 Number of linear chord diagrams having n chords and no chord length larger than four. 2
 1, 1, 3, 15, 105, 315, 1141, 4779, 21101, 80559, 314185, 1267551, 5160933, 20504123, 81554685, 326682775, 1310978305, 5239019143, 20931551661, 83743554723, 335175239813, 1340542340399, 5360923216953, 21444223178271, 85786427569333, 343141430067947 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Alois P. Heinz, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (2,2,11,60,-18,-26,-108,-48) FORMULA G.f.: -(2*x^4+4*x^3+x^2+x-1) / ((4*x-1) * (12*x^7+30*x^6+14*x^5+8*x^4-13*x^3 -6*x^2 -2*x-1)). CROSSREFS Column k=4 of A293960. Sequence in context: A273197 A255427 A181131 * A229726 A145624 A025547 Adjacent sequences:  A293993 A293994 A293995 * A293997 A293998 A293999 KEYWORD nonn,easy AUTHOR Alois P. Heinz, Oct 21 2017 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 June 16 14:16 EDT 2021. Contains 345057 sequences. (Running on oeis4.)