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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A111992 Numerators of row sums of array of rationals A038566(n)/A020653(n), n>=2. 1
 1, 5, 10, 77, 26, 223, 988, 3909, 748, 55991, 5084, 785633, 124658, 207061, 1096792, 29889983, 1893246, 197698279, 85352744, 154834887, 47589202, 325333835, 1188897016, 7612795845, 5775510652, 183259245573, 33778670612 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,2 COMMENTS Denominators are given by A069220. See the W. Lang link under A038566 for the rationals and more. LINKS Table of n, a(n) for n=2..28. FORMULA a(n)=numerator(sum(r(n, k), k=1..phi(n))), with phi(n)=A000010(n) (Euler's totient function) and r(n, k):=A038566(n,k)/A020653(n,k), n>=2, if A020653 is read as an irregular triangle. EXAMPLE Rationals a(n)/A038566(n): [1, 5/2, 10/3, 77/12, 26/5, 223/20, 988/105, 3909/280, 748/63, 55991/2520,...] CROSSREFS Sequence in context: A358491 A316305 A317260 * A325583 A344194 A120598 Adjacent sequences: A111989 A111990 A111991 * A111993 A111994 A111995 KEYWORD nonn,easy AUTHOR Wolfdieter Lang, Sep 12 2005 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 August 2 19:53 EDT 2024. Contains 374875 sequences. (Running on oeis4.)