Original entry on oeis.org
59, 1519, 7814, 17225, 39079, 950619, 977019, 1280699
Offset: 1
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Reap[ For[n = 1, n < 10^5, n++, If[ !Divisible[ Denominator[ HypergeometricPFQ[{1, 1, -n}, {2, 2}, -1]], n+1], Print[n]; Sow[n] ] ] ][[2, 1]] (* Jean-François Alcover, Oct 15 2013 *)
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t=1; for( n=2,10^5, gcd( numerator(t+=(1<1 & print(n-1))
A081528
a(n) = n*lcm{1,2,...,n}.
Original entry on oeis.org
1, 4, 18, 48, 300, 360, 2940, 6720, 22680, 25200, 304920, 332640, 4684680, 5045040, 5405400, 11531520, 208288080, 220540320, 4423058640, 4655851200, 4888643760, 5121436320, 123147264240, 128501493120, 669278610000, 696049754400
Offset: 1
a(2) = 4 because the least common multiple of 1 and 2 is 2, and 2 * 2 = 4.
a(3) = 18 because lcm(1,2,3) = 6, and 3 * 6 = 18.
a(4) = 48 because lcm(1, 2, 3, 4) = 12, and 4 * 12 = 48.
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a(n) := (n + 1)*LCM(VECTOR(k + 1, k, 0, n)) " Paul Barry, Aug 06 2004 "
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Table[n*LCM@@Range[n], {n, 30}] (* Harvey P. Dale, Oct 09 2012 *)
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l=vector(35); l[1]=1; print1("1, "); for(n=2,35, l[n]=lcm(l[n-1],n); print1(n*l[n],", ")) \\ Rick L. Shepherd, Aug 21 2006
A097345
Numerators of the partial sums of the binomial transform of 1/(n+1).
Original entry on oeis.org
1, 5, 29, 103, 887, 1517, 18239, 63253, 332839, 118127, 2331085, 4222975, 100309579, 184649263, 1710440723, 6372905521, 202804884977, 381240382217, 13667257415003, 25872280345103, 49119954154463, 93501887462903
Offset: 0
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Table[ Sum[(2^(k+1)-1)/(k+1), {k, 0, n}] // Numerator, {n, 0, 21}] (* Jean-François Alcover, Oct 14 2013, after Pari *)
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A097345(n) = numerator(sum(k=0,n,(2^(k+1)-1)/(k+1)))
Edited and corrected by Daniel Glasscock (glasscock(AT)rice.edu), Jan 04 2008 and
M. F. Hasler, Jan 25 2008
Moved comment concerning numerators of the logarithm from
A097344 to here where it is correct -
R. J. Mathar, Mar 04 2010
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