OFFSET
0,1
COMMENTS
1 = 2/7 + Sum(n=1,inf.,25/a(n)) = 2/7 + 25/84 + 25/204 + 25/374 + 25/594...+...; with partial sums: 2/7, 7/12, 12/17, 17/22...(5n+2)/(5n+7)...==>1
LINKS
FORMULA
25n^2 + 45n + 14.
MATHEMATICA
Table[(5n+2)(5n+7), {n, 0, 60}] (* or *) LinearRecurrence[{3, -3, 1}, {14, 84, 204}, 60] (* Harvey P. Dale, Jun 17 2023 *)
PROG
(PARI) a(n)=(5*n+2)*(5*n+7) \\ Charles R Greathouse IV, Jun 17 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, Jun 19 2003
EXTENSIONS
Corrected by Douglas McNeil and Charles R Greathouse IV, Aug 31 2010
STATUS
approved