The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A073820 a(n) = n+1-i such that prime(i)*(n+1-i) is maximized (1 <= i <= n). 2
 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; text; 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. LINKS 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: 2*5 = 10 3*4 = 12 5*3 = 15 7*2 = 14 11*1 = 11 The largest product is 15, so a(5) = 3. CROSSREFS Cf. A073818, A073819. Sequence in context: A071995 A114108 A276090 * A103509 A252941 A069898 Adjacent sequences:  A073817 A073818 A073819 * A073821 A073822 A073823 KEYWORD easy,nonn AUTHOR David Wasserman, Aug 13 2002 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 22 14:30 EDT 2021. Contains 343177 sequences. (Running on oeis4.)