A073820 - OEIS

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A073820

a(n) = n+1-i such that prime(i)*(n+1-i) is maximized (1 <= i <= n).

1, 2, 3, 2, 3, 2, 3, 4, 5, 4, 5, 6, 7, 5, 6, 7, 8, 9, 8, 9, 10, 10, 11, 12, 13, 10, 11, 12, 13, 14, 15, 16, 15, 16, 17, 17, 18, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 20, 21, 22, 23, 24, 25, 26, 27, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 32, 33, 31, 30, 31, 32, 33, 34 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`3 is the only n for which the maximum is not unique; a(3) could also be given as 2.`
	FORMULA	`a(n) = A073818(n)/A073819(n).`
	EXAMPLE	`For n = 5, we take the first 5 primes in ascending order and multiply them by the numbers from 5 to 1 in descending order: 25 = 10 34 = 12 53 = 15 72 = 14 11*1 = 11 The largest product is 15, so a(5) = 3.`
	CROSSREFS	`Cf. A073818, A073819.` `Sequence in context: A132423 A071995 A114108 * A103509 A069898 A007978` `Adjacent sequences: A073817 A073818 A073819 * A073821 A073822 A073823`
	KEYWORD	`easy,nonn`
	AUTHOR	`David Wasserman (wasserma(AT)spawar.navy.mil), Aug 13 2002`

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Last modified February 15 03:59 EST 2012. Contains 205694 sequences.