This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A304108 Numbers n such that the (0,1)-polynomial encoded in binary expansion of n has at least one duplicated irreducible divisor when the factorization is done in polynomial ring GF(2)[X]. 4
 4, 5, 8, 10, 12, 15, 16, 17, 20, 21, 24, 27, 28, 30, 32, 34, 36, 39, 40, 42, 44, 45, 48, 51, 52, 54, 56, 57, 60, 63, 64, 65, 68, 69, 72, 75, 76, 78, 80, 81, 84, 85, 88, 90, 92, 95, 96, 99, 100, 102, 104, 105, 107, 108, 112, 114, 116, 119, 120, 124, 125, 126, 128, 130, 132, 135, 136, 138, 140, 141, 144, 147, 148, 150, 151, 152, 153, 156, 160, 162 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Positions of zeros in A091219 and A304109. Numbers n such that A091221(n) < A091222(n). LINKS Antti Karttunen, Table of n, a(n) for n = 1..32768 EXAMPLE 4 is present as 4 = A048720(2,2) = A048720(A014580(1), A014580(1)). 5 is present as 5 = A048720(3,3) = A048720(A014580(2), A014580(2)). 10 is present as 10 = A048720(2,A048720(3,3)). PROG (PARI) isA304108(n) = { my(fm=factor(Pol(binary(n))*Mod(1, 2))); for(k=1, #fm~, if(fm[k, 2] > 1, return(1))); (0); }; k=0; n=0; while(k<100, n++; if(isA304108(n), k++; print1(n, ", "))); CROSSREFS Cf. A304107 (complement). Cf. A014580, A048720, A091219, A091221, A091222, A304109. Cf. also A013929. Sequence in context: A026491 A255491 A292658 * A214026 A174396 A033157 Adjacent sequences:  A304105 A304106 A304107 * A304109 A304110 A304111 KEYWORD nonn AUTHOR Antti Karttunen, May 13 2018 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 August 22 11:34 EDT 2019. Contains 326176 sequences. (Running on oeis4.)