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 A091725 Decimal expansion of second exponential integral at 1, ExpIntegralEi[1]. 45
 1, 8, 9, 5, 1, 1, 7, 8, 1, 6, 3, 5, 5, 9, 3, 6, 7, 5, 5, 4, 6, 6, 5, 2, 0, 9, 3, 4, 3, 3, 1, 6, 3, 4, 2, 6, 9, 0, 1, 7, 0, 6, 0, 5, 8, 1, 7, 3, 2, 7, 0, 7, 5, 9, 1, 6, 4, 6, 2, 2, 8, 4, 3, 1, 8, 8, 2, 5, 1, 3, 8, 3, 4, 5, 3, 3, 8, 0, 4, 1, 5, 3, 5, 4, 8, 9, 0, 0, 7, 1, 0, 1, 2, 6, 1, 3, 8, 9, 5, 6, 9, 7, 1, 8, 1 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Robert Price, Table of n, a(n) for n = 1..10000 Zbigniew Gołębiewski, Mateusz Klimczak, Protection Number of Recursive Trees, 2019 Proceedings of the Sixteenth Workshop on Analytic Algorithmics and Combinatorics (ANALCO). Eric Weisstein's World of Mathematics, Exponential Integral Eric Weisstein's World of Mathematics, Factorial Sums Eric Weisstein's World of Mathematics, Logarithmic Integral FORMULA Equals li(e), where li(x) is the logarithmic integral, and gamma + Sum_{n>=1} 1/(n*n!) = A001620 + A229837. - Amiram Eldar, Mar 05 2019 EXAMPLE 1.89511781635593675546652... MATHEMATICA RealDigits[ExpIntegralEi[1], 10, 105][[1]] (* Robert G. Wilson v, Oct 08 2004 *) PROG (PARI) real(-eint1(-1)) \\ Charles R Greathouse IV, Apr 23 2013 CROSSREFS Cf. A001563, A001620, A229837. Sequence in context: A243267 A243268 A203071 * A029689 A201294 A199383 Adjacent sequences: A091722 A091723 A091724 * A091726 A091727 A091728 KEYWORD nonn,cons AUTHOR Eric W. Weisstein, Feb 01 2004 STATUS approved

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Last modified September 15 16:35 EDT 2024. Contains 375938 sequences. (Running on oeis4.)