1,2
Robert Price, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Exponential Integral
Eric Weisstein's World of Mathematics, Factorial Sums
RealDigits[ExpIntegralEi[1], 10, 105][[1]] (* Robert G. Wilson v, Oct 08 2004 *)
(PARI) real(-eint1(-1)) \\ Charles R Greathouse IV, Apr 23 2013
Sequence in context: A243267 A243268 A203071 * A029689 A201294 A199383
Adjacent sequences: A091722 A091723 A091724 * A091726 A091727 A091728
nonn,cons
Eric W. Weisstein, Feb 01 2004
approved