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A324658
a(n) = n - A324659(n), where A324659(n) is half of bitwise-AND of 2*n and sigma(n).
5
1, 2, 1, 4, 4, 0, 3, 8, 9, 2, 9, 0, 8, 2, 3, 16, 16, 0, 17, 0, 5, 4, 19, 0, 16, 10, 11, 0, 16, 26, 15, 32, 33, 32, 35, 0, 36, 32, 35, 0, 40, 10, 41, 4, 8, 10, 39, 0, 33, 16, 19, 4, 36, 2, 19, 0, 17, 18, 33, 40, 32, 14, 11, 64, 65, 2, 65, 64, 69, 6, 67, 8, 72, 66, 65, 8, 77, 10, 71, 0, 65, 64, 81, 4, 65, 20, 67, 0, 80
OFFSET
1,2
FORMULA
a(n) = n - A324659(n) = n - A318468(n)/2 = n - ((2*n AND sigma(n))/2).
MATHEMATICA
Array[# - BitAnd[2*#, DivisorSigma[1, #]]/2 &, 100] (* Paolo Xausa, Mar 13 2024 *)
PROG
(PARI) A324658(n) = (n-(bitand(2*n, sigma(n))/2));
CROSSREFS
Cf. A324652 (positions of zeros).
Sequence in context: A036069 A338846 A009477 * A105568 A335830 A004175
KEYWORD
nonn,look
AUTHOR
Antti Karttunen, Mar 14 2019
STATUS
approved