This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A091222 Number of irreducible polynomials dividing n-th GF(2)[X]-polynomial, counted with multiplicity. 16
 0, 1, 1, 2, 2, 2, 1, 3, 2, 3, 1, 3, 1, 2, 3, 4, 4, 3, 1, 4, 2, 2, 2, 4, 1, 2, 3, 3, 2, 4, 1, 5, 2, 5, 2, 4, 1, 2, 3, 5, 1, 3, 2, 3, 4, 3, 1, 5, 2, 2, 5, 3, 2, 4, 1, 4, 3, 3, 1, 5, 1, 2, 3, 6, 4, 3, 1, 6, 2, 3, 2, 5, 1, 2, 4, 3, 2, 4, 2, 6, 2, 2, 3, 4, 6, 3, 1, 4, 2, 5, 1, 4, 2, 2, 3, 6, 1, 3, 3, 3, 3, 6 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 A. Karttunen, Scheme-program for computing this sequence. FORMULA a(n) = A001222(A091203(n)) = A001222(A091205(n)). a(A000051(n)) = A091248(n). MAPLE for n from 1 to 1000 do   L:= convert(n, base, 2);   P:= add(L[i]*X^(i-1), i=1..nops(L));   R:= Factors(P) mod 2;   a[n]:= add(r[2], r=R[2]); od: seq(a[n], n=1..1000); # Robert Israel, Jun 07 2015 PROG (PARI) a(n)=my(fm=factor(Pol(binary(n))*Mod(1, 2))); sum(k=1, #fm~, fm[k, 2]) \\ Franklin T. Adams-Watters, Jun 07 2015 CROSSREFS Cf. A000051, A001222, A091203, A091205, A091248. Cf. A256170. Sequence in context: A260372 A037180 A241675 * A294884 A275024 A064659 Adjacent sequences:  A091219 A091220 A091221 * A091223 A091224 A091225 KEYWORD nonn AUTHOR Antti Karttunen, Jan 03 2004 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.