A111992 Numerators of row sums of array of rationals A038566(n)/A020653(n), n>=2.

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

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