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 A304107 Analog for squarefree numbers when n is factored in polynomial ring GF(2)[X], so that the binary expansion of n defines the corresponding (0,1)-polynomial. These are numbers n such that the said polynomial doesn't have any duplicated irreducible divisors. 5
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 OFFSET 1,2 COMMENTS Positions of nonzeros in A091219 and A304109. Numbers n such that A091221(n) = A091222(n). Numbers n that cannot be expressed as n = A048720(k,A000695(m)) for any k >= 0, m >= 2. It seems that a(n) is approximately 2n for large n. See also comments in A304110. LINKS Antti Karttunen, Table of n, a(n) for n = 1..32769 FORMULA For n >= 1, A304110(a(n)) = n. PROG (PARI) A304109(n) = { my(fm=factor(Pol(binary(n))*Mod(1, 2))); for(k=1, #fm~, if(fm[k, 2] > 1, return(0))); (1); }; k=0; n=0; while(k<100, n++; if(A304109(n), k++; print1(n, ", "))); CROSSREFS Cf. A304108 (complement), A304109 (characteristic function), A304110 (least monotonic left inverse). Cf. A000695, A014580, A048720, A091219, A091221, A091222, A304111. Cf. also A005117. Sequence in context: A283208 A259726 A259587 * A181732 A190199 A014873 Adjacent sequences:  A304104 A304105 A304106 * A304108 A304109 A304110 KEYWORD nonn AUTHOR Antti Karttunen, May 13 2018 STATUS approved

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Last modified August 18 07:39 EDT 2019. Contains 326075 sequences. (Running on oeis4.)