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 A099282 Decimal expansion of the cosine integral at 1. 9
 3, 3, 7, 4, 0, 3, 9, 2, 2, 9, 0, 0, 9, 6, 8, 1, 3, 4, 6, 6, 2, 6, 4, 6, 2, 0, 3, 8, 8, 9, 1, 5, 0, 7, 6, 9, 9, 9, 7, 5, 7, 8, 0, 3, 2, 5, 8, 5, 7, 3, 1, 8, 9, 4, 8, 0, 1, 3, 1, 8, 5, 4, 2, 4, 3, 6, 1, 3, 0, 3, 3, 0, 0, 2, 5, 0, 5, 6, 0, 5, 2, 8, 9, 6, 8, 4, 8, 1, 8, 3, 0, 9, 7, 3, 2, 2, 9, 9, 4, 6, 0, 4, 9, 4, 8 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Table of n, a(n) for n=0..104. Eric Weisstein's World of Mathematics, Cosine Integral. FORMULA Equals -real(E_1(I)) = -(E_1(I)+E_1(-I))/2, where E_1(z) = Integral_{t>=1} exp(-t*z)/t dt is the exponential integral. - Stanislav Sykora, May 08 2015 From Amiram Eldar, Jun 25 2021: (Start) Equals -Integral_{x>=1} cos(x)/x dx. Equals gamma - Integral_{x=0..1} (1-cos(x))/x dx, where gamma = A001620. Equals gamma + Sum_{k>=1} (-1)^k/((2*k)*(2*k)!). (End) EXAMPLE I=0.337403922900968134662646203889150769997578032585731894801318542... MATHEMATICA RealDigits[ CosIntegral[1], 10, 105][[1]] PROG (PARI) a = real(-eint1(I)) \\ Stanislav Sykora, May 08 2015 (PARI) -intnum(x=1, [oo, I], cos(x)/x) \\ Charles R Greathouse IV, May 08 2015 CROSSREFS Cf. A001620, A099281, A257535. Sequence in context: A324548 A249383 A187419 * A002937 A085870 A336510 Adjacent sequences: A099279 A099280 A099281 * A099283 A099284 A099285 KEYWORD cons,nonn AUTHOR Robert G. Wilson v, Oct 08 2004 STATUS approved

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Last modified September 17 17:58 EDT 2024. Contains 375990 sequences. (Running on oeis4.)