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A003102
Largest number divisible by all numbers < its n-th root.
(Formerly M2139)
2
2, 24, 420, 27720, 720720, 36756720, 5354228880, 481880599200, 25619985190800, 10685862914126400, 876240758958364800, 113035057905629059200, 24792356033967973651200, 9690712164777231700912800, 2364533768205644535022723200, 396059406174445459616306136000
OFFSET
1,1
REFERENCES
A. Murthy, An application of Smarandache LCM sequence and the largest number divisible by all the integers not exceeding the r-th root, Preprint.
N. Ozeki, On the problem 1, 2, 3, ..., [ n^(1/k) ] | n, Journal of the College of Arts and Sciences, Chiba University (Chiba, Japan), Vol. 3, No. 4 (Sept. 1962), pp. 427-431 [ Math. Rev. 30 213(1085) 1965 ].
J. Roberts, Lure of the Integers, Math. Assoc. America, 1992, p. 277.
D. O. Shklyarsky, N. N. Chentsov and I. M. Yaglom, Selected Problems and Theorems in Elementary Mathematics; Problem 78; Mir Publishers, Moscow.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
A. Murthy, Some New Smarandache Sequences, Functions and Partitions, Smarandache Notions Journal, Vol. 11, No. 1-2-3, Spring 2000, p. 179.
N. Ozeki, On the problem 1, 2, 3, ..., [ n^(1/k) ] | n, Journal of the College of Arts and Sciences, Chiba University (Chiba, Japan), Vol. 3, No. 4 (Sept. 1962), pp. 427-431 [ Math. Rev. 30 213(1085) 1965 ]. [Annotated scanned copy]
D. L. Silverman, Problem 159, Pi Mu Epsilon Journal, Vol. 4, No. 3, Fall 1965, p. 124.
D. L. Silverman, Problem 159, Pi Mu Epsilon Journal, Vol. 4, No. 3, Fall 1965, p. 124. [Annotated scanned copy]
FORMULA
It has been shown that a(n) < {p(2n)}^n, where p(2n) is the (2n)-th prime. - Amarnath Murthy, Apr 26 2001
MATHEMATICA
k=1; lc=1; Table[While[r=Floor[lc^(1/n)]; Union[Mod[lc, Range[r]]]=={0}, k++; good=lc; lc=LCM[lc, k]]; m=2; While[r=Floor[(m*good)^(1/n)]; Union[Mod[m*good, Range[r]]]=={0}, m++ ]; m=m-1; m*good, {n, 50}] - T. D. Noe, Aug 01 2006
CROSSREFS
Sequence in context: A219431 A214688 A364195 * A370847 A304318 A337505
KEYWORD
nonn,nice
AUTHOR
N. J. A. Sloane, H. W. Gould
EXTENSIONS
Corrected and extended by T. D. Noe, Aug 01 2006
STATUS
approved