This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A125093 Triangle T(n,k) = n*A054525(n,k) read by rows. 4
 1, -2, 2, -3, 0, 3, 0, -4, 0, 4, -5, 0, 0, 0, 5, 6, -6, -6, 0, 0, 6, -7, 0, 0, 0, 0, 0, 7, 0, 0, 0, -8, 0, 0, 0, 8, 0, 0, -9, 0, 0, 0, 0, 0, 9, 10, -10, 0, 0, -10, 0, 0, 0, 0, 10, -11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 11, 0, 12, 0, -12, 0, -12, 0, 0, 0, 0, 0, 12, -13, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 13, 14, -14, 0, 0, 0, 0, -14, 0, 0, 0, 0, 0, 0, 14, 15, 0, -15, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS FORMULA T(n,1) = n*mu(n) = A055615(n). EXAMPLE First few rows of the triangle are: 1; -2, 2; -3, 0, 3; 0, -4, 0, 4; -5, 0, 0, 0, 5; 6, -6, -6, 0, 0, 6; -7, 0, 0, 0, 0, 0, 7; ... MAPLE A125093 := proc(n, k) if n = k then n; elif n mod k = 0 then n*numtheory[mobius](n/k) ; else 0; end if; end proc: seq(seq(A125093(n, k), k=1..n), n=1..16) ; # R. J. Mathar, Apr 10 2011 CROSSREFS Cf. A055615, A051731, A127648. Sequence in context: A053761 A138067 A324348 * A294898 A297114 A318448 Adjacent sequences:  A125090 A125091 A125092 * A125094 A125095 A125096 KEYWORD tabl,easy,sign AUTHOR Gary W. Adamson, Jan 22 2007 EXTENSIONS Offset and definition corrected by R. J. Mathar, Apr 10 2011 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 March 21 04:59 EDT 2019. Contains 321364 sequences. (Running on oeis4.)