A059031 Fifth main diagonal of A059026: a(n) = B(n+4,n) = lcm(n+4,n)/(n+4) + lcm(n+4,n)/n - 1 for all n >= 1.

5, 3, 9, 2, 13, 7, 17, 4, 21, 11, 25, 6, 29, 15, 33, 8, 37, 19, 41, 10, 45, 23, 49, 12, 53, 27, 57, 14, 61, 31, 65, 16, 69, 35, 73, 18, 77, 39, 81, 20, 85, 43, 89, 22, 93, 47, 97, 24, 101, 51, 105, 26, 109, 55, 113, 28, 117, 59, 121, 30, 125, 63, 129, 32, 133, 67

Offset

1,1

Links

Table of n, a(n) for n=1..66.

Index entries for linear recurrences with constant coefficients, signature (0,0,0,2,0,0,0,-1).

Formula

a(2n+1) = 4n+5, a(4n+2) = 4n+3, a(4n+4) = 4n+2. - Ralf Stephan, Jun 10 2005

G.f.: -x*(-5-3*x-9*x^2-2*x^3-3*x^4-x^5+x^6) / ( (x-1)^2*(1+x)^2*(x^2+1)^2 ). - R. J. Mathar, Sep 20 2011

Maple

B := (n, m) -> lcm(n, m)/n + lcm(n, m)/m - 1: seq(B(m+4, m), m=1..90);

Mathematica

LinearRecurrence[{0, 0, 0, 2, 0, 0, 0, -1}, {5, 3, 9, 2, 13, 7, 17, 4}, 70] (* Harvey P. Dale, Aug 19 2019 *)

Crossrefs

Cf. A059026, A059029, A059030.

Sequence in context: A241624 A159275 A374990 * A245516 A073243 A134943

Adjacent sequences: A059028 A059029 A059030 * A059032 A059033 A059034

Keyword

nonn,easy

Author

Asher Auel, Dec 15 2000

Status

approved