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 A331532 a(n) is the number of nonnegative integers k such that (n^2) AND (k^2) = k^2 (where AND denotes the bitwise AND operator). 2
 1, 2, 2, 3, 2, 5, 3, 4, 2, 5, 5, 9, 3, 4, 4, 4, 2, 4, 5, 7, 5, 12, 9, 4, 3, 9, 4, 11, 4, 7, 4, 6, 2, 5, 4, 7, 5, 12, 7, 15, 5, 7, 12, 13, 9, 17, 4, 3, 3, 7, 9, 4, 4, 20, 11, 15, 4, 8, 7, 12, 4, 5, 6, 6, 2, 4, 5, 7, 4, 11, 7, 14, 5, 12, 12, 29, 7, 8, 15, 5, 5 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Equivalently, this is the number of nonnegative integers k such that (n^2) OR (k^2) = n^2 (where OR denotes the bitwise OR operator); this connects this sequence to A001316. LINKS Rémy Sigrist, Table of n, a(n) for n = 0..8192 FORMULA a(2^k) = 2 for any k >= 0. a(n) <= n+1. EXAMPLE For n = 7: - we have:   k  7^2 AND k^2   -  -----------   0  0 = 0   1  1 = 1   2  0 <> 4   3  1 <> 9   4  16 = 16   5  17 <> 25   6  32 <> 36   7  49 = 49 - hence a(7) = 4. PROG (PARI) a(n) = sum(k=0, n, bitand(n^2, k^2)==k^2) CROSSREFS Cf. A001316, A331533 (corresponding k's). Sequence in context: A025478 A084371 A025476 * A078773 A151663 A162753 Adjacent sequences:  A331529 A331530 A331531 * A331533 A331534 A331535 KEYWORD nonn,base AUTHOR Rémy Sigrist, Jan 19 2020 STATUS approved

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Last modified December 2 03:22 EST 2020. Contains 338865 sequences. (Running on oeis4.)