id:A085818 - OEIS Search Results

Search: id:A085818

Displaying 1-1 of 1 results found.

page 1

For n>1: a(n) = if (n=p^e with p prime and e>1) then p else (n-m)-th prime, where m = number of nonprime prime powers <=n; a(1)=1.

+0
4

1, 2, 3, 2, 5, 7, 11, 2, 3, 13, 17, 19, 23, 29, 31, 2, 37, 41, 43, 47, 53, 59, 61, 67, 5, 71, 3, 73, 79, 83, 89, 2, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 7, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241 (list; graph; listen)

	OFFSET	`1,2`
	COMMENT	`a(n) = if (n=p^e with p prime and e>1) then A025473(n) else A008578(n-A085501(n));` `n divides A085819(n)=Prod(a(k): k<=n), as by construction: a(1)=1; if n divides A085819(n-1) then a(n) = smallest prime not occurring earlier; if n does not divide A085819(n-1) then a(n) = greatest prime factor of n (A006530);` `A000040 occurs infinitly many times as a subsequence.` `a(A085971(n))=A000040(n) and for all k>1: a(A000040(n)^k)=A000040(n); A085985(n)=A049084(a(n)). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jul 06 2003`
	CROSSREFS	`Sequence in context: A092556 A092550 A058977 this_sequence A064939 A151549 A086989` `Adjacent sequences: A085815 A085816 A085817 this_sequence A085819 A085820 A085821`
	KEYWORD	`nonn`
	AUTHOR	`Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jul 04 2003`

page 1

Search completed in 0.002 seconds

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

AT&T Labs Research