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!)
 A164678 Convolve A008619 with sequences which map to 2,3,5,7,11,13,17... A000040 then, by bending when needed, summarize the results in a triangular array. 1
 1, 2, 1, 5, 4, 2, 9, 8, 6, 2, 17, 16, 14, 9, 3, 28, 27, 25, 20, 12, 3, 47, 46, 44, 39, 30, 16, 4, 73, 72, 70, 65, 56, 40, 20, 4, 114, 113, 111, 106, 97, 80, 55, 25, 5, 170, 169, 167, 162, 153, 136, 109, 70, 30, 5, 253, 252, 250, 245, 236, 219, 191, 147, 91, 36, 6, 365 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Sequence A164680 is not in the triangle since 45 = 3*15 and 15 is not a member of A000040 (the prime numbers). LINKS EXAMPLE The desired triangle begins: .1 .2..1 .5..4..2 .9..8..6..2 17.16.14..9..3 28.27.25.20.12..3 47.46.44.39.30.16..4 etc. Note that 21 = 3*7 maps to 1,2,5,9,17,27,44,... A139672 is embedded in the triangle. CROSSREFS Cf. A008619 A002620 A006918 A097701 A139672 ... A000097 (embedded sequences). Sequence in context: A103718 A113350 A227372 * A164679 A275183 A275131 Adjacent sequences:  A164675 A164676 A164677 * A164679 A164680 A164681 KEYWORD nonn,tabl,uned AUTHOR Alford Arnold, Aug 25 2009 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 February 19 22:36 EST 2020. Contains 332061 sequences. (Running on oeis4.)