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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A137791 Number of ways to write n as sum of two positive numbers having no prime gaps in their factorization. 4
 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 4, 5, 5, 6, 5, 6, 6, 7, 7, 8, 7, 7, 6, 8, 7, 8, 7, 8, 7, 9, 9, 10, 9, 10, 9, 11, 9, 11, 9, 10, 9, 11, 10, 10, 8, 10, 10, 13, 11, 12, 9, 11, 10, 14, 11, 12, 8, 10, 10, 14, 12, 13, 9, 12, 12, 14, 11, 12, 8, 11, 10, 16, 12, 11, 10, 14, 14, 16, 14, 14, 9, 13, 14, 18 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 LINKS R. Zumkeller, Table of n, a(n) for n = 1..10000 EXAMPLE a(20) = #{1+19,2+18,3+17,4+16,5+15,7+13,8+12,9+11} = 8; a(21) = #{2+19,3+18,4+17,5+16,6+15,8+13,9+12} = 7; a(22) = #{3+19,4+18,5+17,6+16,7+15,9+13,11+11} = 7; a(23) = #{4+19,5+18,6+17,7+16,8+15,11+12} = 6; a(24) = #{1+23,5+19,6+18,7+17,8+16,9+15,11+13,12+12} = 8. CROSSREFS Cf. A073491, A002375, A061358, A071330, A137792, A137793. Sequence in context: A336430 A167232 A319468 * A096125 A140828 A262907 Adjacent sequences:  A137788 A137789 A137790 * A137792 A137793 A137794 KEYWORD nonn AUTHOR Reinhard Zumkeller, Feb 11 2008 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 January 24 00:05 EST 2022. Contains 350515 sequences. (Running on oeis4.)