This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A127639 A051731 * A127640, where A127640 = infinite lower triangular matrix with the sequence of primes in the main diagonal and the rest zeros. 5
 2, 2, 3, 2, 0, 5, 2, 3, 0, 7, 2, 0, 0, 0, 11, 2, 3, 5, 0, 0, 13, 2, 0, 0, 0, 0, 0, 17, 2, 3, 0, 7, 0, 0, 0, 19, 2, 0, 5, 0, 0, 0, 0, 0, 23, 2, 3, 0, 0, 11, 0, 0, 0, 0, 29, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 31, 2, 3, 5, 7, 0, 13, 0, 0, 0, 0, 0, 37, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 41, 2, 3, 0, 0, 0, 0, 17, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Row sums = A007445, inverse Mobius transform of the primes: (2, 5, 7, 12, 13, 23,...) LINKS EXAMPLE First few rows of the triangle are: 2; 2, 3; 2, 0, 5; 2, 3, 0, 7; 2, 0, 0, 0, 11; 2, 3, 5, 0, 0, 13; ... MAPLE A051731 := proc(n, k) if n mod k = 0 then 1 ; else 0 ; fi ; end: A127639 := proc(n, k) A051731(n, k)*ithprime(k) ; end: for n from 1 to 16 do for k from 1 to n do printf("%d, ", A127639(n, k)) ; od ; od ; - R. J. Mathar, Mar 14 2007 CROSSREFS Cf. A051731, A007445, A127639. Sequence in context: A007906 A098008 A127638 * A100890 A076494 A217721 Adjacent sequences:  A127636 A127637 A127638 * A127640 A127641 A127642 KEYWORD nonn,tabl,easy AUTHOR Gary W. Adamson, Jan 21 2007 EXTENSIONS More terms from R. J. Mathar, Mar 14 2007 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .