id:A075753 - OEIS Search Results

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Smallest prime factor of n-th odd triangular number.

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3, 3, 3, 3, 5, 7, 3, 3, 3, 3, 11, 5, 3, 3, 3, 3, 5, 19, 3, 3, 3, 3, 23, 5, 3, 3, 3, 3, 29, 31, 3, 3, 3, 3, 5, 37, 3, 3, 3, 3, 41, 5, 3, 3, 3, 3, 5, 7, 3, 3, 3, 3, 53, 5, 3, 3, 3, 3, 7, 11, 3, 3, 3, 3, 5, 7, 3, 3, 3, 3, 11, 5, 3, 3, 3, 3, 5, 79, 3, 3, 3, 3, 83, 5, 3, 3, 3, 3, 89, 7, 3, 3, 3, 3, 5, 97, 3, 3, 3 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`As A014493(n)=binomial(A042963(n),2) and a(n)=A020639(A014493(n))>2, A014493(n) is a good binomial coefficient.`
	LINKS	`Eric Weisstein's World of Mathematics, Triangular Number.` `Eric Weisstein's World of Mathematics, Good Binomial Coefficient.` `Eric Weisstein's World of Mathematics, Least Prime Factor.`
	CROSSREFS	`Cf. A069901.` `Sequence in context: A130821 A129756 A156724 this_sequence A006166 A142716 A079084` `Adjacent sequences: A075750 A075751 A075752 this_sequence A075754 A075755 A075756`
	KEYWORD	`nonn`
	AUTHOR	`Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 11 2003`

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Last modified December 15 00:47 EST 2009. Contains 170825 sequences.

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