The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A091828 a(n)=n-2*valuation(A000254(n),3). 0
 1, 0, 3, 4, 5, 2, 1, 4, 5, 6, 7, 6, 7, 8, 7, 8, 9, 4, 5, 6, 3, 2, 5, 6, 7, 8, 7, 8, 9, 8, 9, 10, 9, 10, 11, 8, 9, 10, 9, 10, 11, 10, 11, 12, 9, 10, 11, 10, 11, 12, 11, 12, 13, 6, 7, 8, 7, 8, 9, 8, 9, 10, 5, 6, 7, 4, 5, 6, 7, 8, 9, 8, 9, 10, 9, 10, 11, 10, 11, 12, 9, 10, 11, 10, 11, 12, 11, 12, 13 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS FORMULA For n>7 a(3n)=a(n)+2; a(3n+1)=a(n)+3; (3n+2)=a(n)+4 PROG (PARI) a(n)=if(n<2, 1, n-2*valuation(n!*sum(i=1, n, 1/i), 3)) CROSSREFS Cf. A056792. Sequence in context: A144786 A247369 A009389 * A305972 A121845 A239639 Adjacent sequences: A091825 A091826 A091827 * A091829 A091830 A091831 KEYWORD nonn AUTHOR Benoit Cloitre, Mar 09 2004 STATUS approved

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

Last modified March 20 14:36 EDT 2023. Contains 361384 sequences. (Running on oeis4.)