OFFSET
0,1
COMMENTS
EXAMPLE
1/4 + 1/8 + 1/13 + ... = (1/34)(17 + 8r*tan(r)), where r = (pi/2)sqrt(17)
1/4 + 1/8 + 1/13 + ... = 0.79841055101687800386526651756132658166...
MATHEMATICA
$MaxExtraPrecision = Infinity; t[n_, k_] := t[n, k] = n + (n + k - 2) (n + k - 1)/2; u = N[Sum[1/t[n, 3], {n, 1, Infinity}], 130]; RealDigits[u, 10]
PROG
(PARI) sumnumrat(2/(n^2+5*n+2), 1) \\ Charles R Greathouse IV, Feb 08 2023
CROSSREFS
KEYWORD
AUTHOR
Clark Kimberling, Aug 06 2013
STATUS
approved