id:A120303 - OEIS Search Results

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A120303

Largest prime factor of Catalan number A000108[n].

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2, 5, 7, 7, 11, 13, 13, 17, 19, 19, 23, 23, 23, 29, 31, 31, 31, 37, 37, 41, 43, 43, 47, 47, 47, 53, 53, 53, 59, 61, 61, 61, 67, 67, 71, 73, 73, 73, 79, 79, 83, 83, 83, 89, 89, 89, 89, 97, 97, 101, 103, 103, 107, 109, 109, 113, 113, 113, 113, 113, 113, 113, 127, 127, 131, 131 (list; graph; listen)

	OFFSET	`2,1`
	COMMENT	`All prime numbers are present in a(n) in their natural order with repetition. The number of repetitions is equal to A028334[n]: differences between consecutive primes, divided by 2. - Alexander Adamchuk (alex(AT)kolmogorov.com), Jul 30 2006`
	FORMULA	`a(n) = Max[FactorInteger[(2n)!/n!/(n+1)! ]]. a(n) = A060308[n] = A060265[n] for n>2.`
	MATHEMATICA	`Table[Max[FactorInteger[(2n)!/n!/(n+1)! ]], {n, 2, 100}]`
	CROSSREFS	`Cf. A000108, A060308, A060265, A020482.` `Cf. A028334.` `Sequence in context: A096624 A145378 A069887 this_sequence A093413 A004099 A084959` `Adjacent sequences: A120300 A120301 A120302 this_sequence A120304 A120305 A120306`
	KEYWORD	`nonn`
	AUTHOR	`Alexander Adamchuk (alex(AT)kolmogorov.com), Jul 13 2006`

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Last modified November 27 14:50 EST 2009. Contains 167570 sequences.

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