login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A168395
Moebius function of odd interprimes (A072569).
0
0, 1, 1, 1, 0, 1, 0, 1, 0, -1, 1, 1, -1, -1, 1, 1, 0, -1, 0, 1, 0, 0, 0, 1, 1, -1, 0, 0, 1, 0, -1, 1, -1, 1, 0, 1, 1, -1, 0, -1, 1, 0, 1, -1, 1, -1, 0, -1, 0, 1, 1, 0, 0, -1, 1, -1, -1, 0, -1, 1, 1, -1, -1, 1, 1, 0, -1, -1, 1, 0, 1, 0, 1, -1, 1, 0, 1, 0, 0, 0, -1, 0, 1, 0, -1, -1, 1, 1, 1, -1, 1, 1, 0
OFFSET
1,1
MAPLE
ts_fip_lih:=proc(n) local i, an, tren: an:=[ ]: for i from 2 to n do tren:=(ithprime(i)+ithprime(i+1))/2: if (tren mod 2 <> 0) then # an:=[ op(an), tren ]: an:=[ op(an), numtheory[mobius](tren) ]: fi: od: RETURN(an) end: ts_fip_lih(2000);
CROSSREFS
Cf. A008683.
Sequence in context: A167392 A190201 A189702 * A378901 A278718 A130854
KEYWORD
sign
AUTHOR
Jani Melik, Nov 24 2009
STATUS
approved