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A326302
a(n) = lcm(n, r(n)) where r(n) = A030101(n) corresponds to the binary reversal of n.
1
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 143, 12, 143, 14, 15, 16, 17, 18, 475, 20, 21, 286, 667, 24, 475, 286, 27, 28, 667, 30, 31, 32, 33, 34, 245, 36, 1517, 950, 741, 40, 1517, 42, 2279, 572, 45, 1334, 2867, 48, 245, 950, 51, 572, 2279, 54, 3245, 56, 741, 1334, 3245
OFFSET
0,3
LINKS
FORMULA
a(n) >= n with equality iff n belongs to A057890.
a(n) < A062383(n)*n. - Robert Israel, Oct 17 2019
EXAMPLE
For n = 35:
- the binary reversal of 35 ("100011" in binary) is 49 ("110001" in binary),
- hence a(35) = lcm(35, 49) = lcm(5*7, 7^2) = 5*7^2 = 245.
MAPLE
f:= proc(n) local L, j;
L:= convert(n, base, 2);
ilcm(n, add(2^(j-1)*L[-j], j=1..nops(L)))
end proc:
map(f, [$0..100]);
PROG
(PARI) a(n, base=2) = lcm(n, fromdigits(Vecrev(digits(n, base)), base))
CROSSREFS
Cf. A030101, A057890 (fixed points), A161825 (GCD variant), A068634 (decimal variant).
Cf. A062383.
Sequence in context: A061378 A004872 A078295 * A004883 A004894 A004905
KEYWORD
nonn,base,look
AUTHOR
Rémy Sigrist, Oct 17 2019
STATUS
approved