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 A354305 a(n) is the denominator of Sum_{k=0..n} (-1)^k / (k!)^2. 2
 1, 1, 4, 9, 192, 1800, 103680, 529200, 232243200, 8230118400, 1463132160000, 39833773056000, 20858412072960000, 1615657835151360000, 584619573580922880000, 1908495817772544000000, 29184209113159670169600000, 3953548328298349068288000000, 185476873609942457647104000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Table of n, a(n) for n=0..18. FORMULA Denominators of coefficients in expansion of BesselJ(0,2*sqrt(x)) / (1 - x). EXAMPLE 1, 0, 1/4, 2/9, 43/192, 403/1800, 23213/103680, 118483/529200, 51997111/232243200, 1842647621/8230118400, ... MATHEMATICA Table[Sum[(-1)^k/(k!)^2, {k, 0, n}], {n, 0, 18}] // Denominator nmax = 18; CoefficientList[Series[BesselJ[0, 2 Sqrt[x]]/(1 - x), {x, 0, nmax}], x] // Denominator Accumulate[Table[(-1)^k/(k!)^2, {k, 0, 20}]]//Denominator (* Harvey P. Dale, Apr 25 2023 *) CROSSREFS Cf. A001044, A053556, A061355, A073701, A091681, A143383, A354303, A354304 (numerators). Sequence in context: A318616 A029738 A067072 * A080438 A029999 A006280 Adjacent sequences: A354302 A354303 A354304 * A354306 A354307 A354308 KEYWORD nonn,frac AUTHOR Ilya Gutkovskiy, May 23 2022 STATUS approved

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Last modified April 15 00:51 EDT 2024. Contains 371667 sequences. (Running on oeis4.)