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 A219325 Positive integers n that are equal to the determinant of the circulant matrix formed by the binary digits of n. 6
 1, 17298, 25947, 100990, 106090, 2718340, 36680364, 34505916416 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Table of n, a(n) for n=1..8. Giovanni Resta, Illustration of a(8) EXAMPLE Binary digits of 17298 are [1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0]. The 15 X 15 circulant matrix formed by their circular right rotations has determinant equal to 17298. MATHEMATICA dcmQ[n_]:=Module[{idn2=IntegerDigits[n, 2]}, Det[Table[RotateRight[idn2, k], {k, Length[ idn2]}]] == n]; Select[Range[3*10^6], dcmQ] (* This program generates the first 6 terms of the sequence. To generate a(7) and a(8), increase the Range constant to 3451*10^7, but the program will take a long time to run. *) (* Harvey P. Dale, Jul 30 2019 *) CROSSREFS Cf. A219324 (decimal version) provides references and more details. Sequence in context: A230164 A001381 A219357 * A255780 A023942 A322858 Adjacent sequences: A219322 A219323 A219324 * A219326 A219327 A219328 KEYWORD base,nonn,nice,more AUTHOR Max Alekseyev, Nov 17 2012 EXTENSIONS a(7) from Hans Havermann and Emmanuel Vantieghem, Nov 19 2012 a(8) from Giovanni Resta, Dec 14 2012 STATUS approved

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Last modified July 15 16:36 EDT 2024. Contains 374333 sequences. (Running on oeis4.)