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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A368672 Total number of lattice paths from (0,0) to (k,n-k) for k=0..n using steps (i,j) with i,j>=0 and gcd(i,j)=1. 2
 1, 2, 5, 14, 39, 110, 307, 860, 2407, 6736, 18851, 52758, 147651, 413224, 1156469, 3236546, 9057955, 25350028, 70945807, 198552344, 555678123, 1555147480, 4352310421, 12180584958, 34089170027, 95403588336, 267001063969, 747242000068, 2091267346883, 5852721227868 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Alois P. Heinz, Table of n, a(n) for n = 0..700 FORMULA a(n) mod 2 = 1 - (n mod 2) = A059841(n). a(n) ~ c * d^n, where d = 2.798648023933224047287803536948757710187420348758496337690531870498937575... and c = 0.639525188357518889842205998775477309094300590250850025271938769053628196... - Vaclav Kotesovec, Jan 13 2024 MAPLE b:= proc(n, k) option remember; `if`(min(n, k)=0, 1, add(add( `if`(igcd(i, j)=1, b(n-i, k-j), 0), j=0..k), i=0..n)) end: a:= n-> add(b(k, n-k), k=0..n): seq(a(n), n=0..29); CROSSREFS Row sums of A362242. Cf. A059841. Sequence in context: A202207 A132834 A000641 * A026135 A201778 A367655 Adjacent sequences: A368669 A368670 A368671 * A368673 A368674 A368675 KEYWORD nonn AUTHOR Alois P. Heinz, Jan 02 2024 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 April 16 20:04 EDT 2024. Contains 371754 sequences. (Running on oeis4.)