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 A088679 a(n) = a(n-1)^2 * n / (n-1), n>1, a(0) = 0, a(1) = 1. 2
 0, 1, 2, 6, 48, 2880, 9953280, 115579079884800, 15266884236590834264309760000, 262212473580148912869121218589990322256745385164800000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Unreduced numerators of: f(1) = 1, f(n) = f(n-1) + f(n-1)/(n-1). - Daniel Suteu, Jul 29 2016 LINKS FORMULA a(n) is asymptotic to c^(2^n)*(1-1/n+2/n^2-6/n^3+25/n^4-137/n^5+...) where c=1.28906475773... and coefficient of n^-k is (-1)^k*A084784(k). a(0) = 0, a(1) = 1, a(n) = n * Product i=1..(n-1) a(i) for n > 1. - Gerald McGarvey, Jun 11 2004 Corrected by Jaroslav Krizek, Oct 16 2009 a(n)^2 = n * A052129(n). Michael Somos, May 13 2012 a(n+1)/A052129(n) = n+1. - Daniel Suteu, Jul 29 2016 EXAMPLE x + 2*x^2 + 6*x^3 + 48*x^4 + 2880*x^5 + 9953280*x^6 + ... MATHEMATICA Join[{0}, RecurrenceTable[{a[1]==1, a[n]==a[n-1]^2 n/(n-1)}, a, {n, 10}]] (* Harvey P. Dale, Jan 16 2015 *) PROG (PARI) {a(n) = if( n<2, n>0, a(n-1)^2 * n / (n-1))} CROSSREFS Cf. A052129. Sequence in context: A230053 A245283 A126023 * A161766 A074020 A080310 Adjacent sequences:  A088676 A088677 A088678 * A088680 A088681 A088682 KEYWORD nonn AUTHOR Michael Somos, Oct 05 2003 STATUS approved

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Last modified October 23 11:19 EDT 2019. Contains 328345 sequences. (Running on oeis4.)