login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A076360 a(n)=Commutator[sigma,tau](n)=d0[d1[w]]-d1[d0[w]], where d0()=number of, d1()=sum of divisors of n. 6
0, -1, 0, -2, 1, -1, 1, -3, -2, -1, 3, -6, 1, 1, 1, -4, 3, -8, 3, -4, -1, 2, 5, -3, -2, 1, 1, -4, 5, -3, 3, -6, 3, 1, 3, -9, 1, 5, 1, -3, 5, -3, 3, 0, -4, 5, 7, -12, 0, -8, 5, -6, 5, 1, 5, 1, 3, 5, 9, -12, 1, 5, -4, -6, 5, 0, 3, 0, 5, 0, 9, -20, 1, 1, -6, 0, 5, 1, 7, -10, -3, 5, 9, -16, 5, 5, 9, 3, 9, -16, 3, 4, 1, 8, 9, -10, 3, -6, 0, -9, 5, 1, 5, 1, -1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..105.

MATHEMATICA

d0[x_] := DivisorSigma[0, x] d1[x_] := DivisorSigma[1, x] Table[d0[d1[w]]-d1[d0[w]], {w, 1, 128}]

CROSSREFS

Cf. A000005, A000203.

Sequence in context: A183214 A086291 A016442 * A089398 A047040 A047020

Adjacent sequences:  A076357 A076358 A076359 * A076361 A076362 A076363

KEYWORD

easy,sign

AUTHOR

Labos E. (labos(AT)ana.sote.hu), Oct 08 2002

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 .

Last modified May 23 09:11 EDT 2013. Contains 225586 sequences.