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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A218855 Imaginary part of the arithmetic derivative for the triangle of Gaussian integers z = r + i*I, with r >= 0 and i >= 0. 4
 0, 0, 0, -2, 0, 2, 0, 0, 0, 1, -8, -2, 0, 2, 8, -3, 0, 0, 0, 0, 3, -6, -3, -2, 1, 2, 3, 8, 0, 0, 0, -2, 2, 0, 0, 1, -24, -5, -8, -2, 0, 2, 8, 5, 24, 0, -4, 0, 1, 0, 0, 2, 0, 4, 6, -16, -5, -6, -3, -2, 0, 2, 3, 6, 5, 16, 0, 0, -3, 0, -3, 0, 0, 3, 0, 3, 0, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS The real part is in A218854. Consult A099379 for the arithmetic derivative of Gaussian integers. LINKS T. D. Noe, Rows n = 0..100 of triangle, flattened EXAMPLE Triangle: 0 0, 0 -2, 0, 2 0, 0, 0, 1 -8, -2, 0, 2, 8 -3, 0, 0, 0, 0, 3 -6, -3, -2, 1, 2, 3, 8 0, 0, 0, -2, 2, 0, 0, 1 MATHEMATICA di[0]=0; di[1]=0; di[ -1]=0; di[I]=0; di[ -I]=0; di[n_] := Module[{f, unt}, f=FactorInteger[n, GaussianIntegers->True]; unt=(Abs[f[[1, 1]]]==1); If[unt, f=Delete[f, 1]]; f=Transpose[f]; Plus@@(n*f[[2]]/f[[1]])]; Im[Table[di[n-i + I*i], {n, 0, 12}, {i, 0, n}]] CROSSREFS Cf. A099379, A099380. Sequence in context: A231715 A137678 A359893 * A069517 A193526 A160498 Adjacent sequences: A218852 A218853 A218854 * A218856 A218857 A218858 KEYWORD sign,tabl AUTHOR T. D. Noe, Nov 09 2012 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 July 18 13:57 EDT 2024. Contains 374378 sequences. (Running on oeis4.)