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 A140451 a(1) = 1. a(n) = the smallest positive multiple of a(n-1) with exactly n 1's in its binary representation. 1
 1, 3, 21, 105, 4305, 21525, 5316675, 3291021825, 38046409656325181475 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Each term is odd. a(10) = 2^617 + 2^529 + 2^527 + 2^401 + 2^352 + 2^284 + 2^240 + 2^239 + 2^154 + 1 has 186 decimal digits. - Max Alekseyev, Feb 04 2018 The sequence is infinite. - Max Alekseyev, Feb 04 2018 LINKS Max Alekseyev, Table of n, a(n) for n = 1..10 CROSSREFS Sequence in context: A134057 A128281 A034268 * A054147 A233582 A043012 Adjacent sequences:  A140448 A140449 A140450 * A140452 A140453 A140454 KEYWORD base,nonn AUTHOR Leroy Quet, Jul 21 2008 EXTENSIONS First 8 terms calculated by R. J. Mathar and Jack Brennen. a(9) from Max Alekseyev, Jul 22 2008 STATUS approved

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Last modified August 13 22:57 EDT 2020. Contains 336473 sequences. (Running on oeis4.)