The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A309846 Number of degree n polynomials f with all nonzero coefficients equal to 1 such that f(k) is divisible by 4 for all integers k. 0
 0, 0, 0, 0, 1, 2, 6, 10, 20, 32, 64, 120, 256, 512, 1056, 2080, 4160, 8192, 16384, 32640, 65536, 131072 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,6 COMMENTS Equivalently, this counts strings of numbers of length n that start with a 1 and which yield a multiple of 4 when read in any base. Conjecture: All terms are of the form 2^(n-5), 2^k*(2^(n-k-5) + 1), or 2^k*(2^(n-k-5) - 1) for some value of k. LINKS EXAMPLE For n = 7, the a(7) = 6 (0,1)-polynomials of degree seven such that f(0) == f(1) == f(2) == f(3) == 0 (mod 3) are x^7 + x^6 + x^5 + x^4, x^7 + x^6 + x^4 + x^3, x^7 + x^6 + x^5 + x^2, x^7 + x^5 + x^4 + x^2, x^7 + x^6 + x^3 + x^2, and x^7 + x^4 + x^3 + x^2. CROSSREFS Cf. A329126, A329479. Sequence in context: A211982 A096338 A198381 * A309874 A317759 A014279 Adjacent sequences:  A309843 A309844 A309845 * A309847 A309848 A309849 KEYWORD nonn,more AUTHOR Peter Kagey, Nov 18 2019 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 February 25 20:04 EST 2020. Contains 332258 sequences. (Running on oeis4.)