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A324648
a(n) = n - A318458(n), where A318458(n) is bitwise-AND of n and the sum of proper divisors of n (sigma(n)-n).
4
1, 2, 2, 4, 4, 0, 6, 8, 9, 2, 10, 12, 12, 4, 6, 16, 16, 2, 18, 0, 20, 16, 22, 24, 25, 10, 18, 0, 28, 20, 30, 32, 32, 34, 34, 0, 36, 32, 38, 8, 40, 8, 42, 4, 12, 36, 46, 48, 49, 16, 34, 16, 52, 52, 38, 56, 40, 26, 58, 16, 60, 28, 22, 64, 64, 0, 66, 68, 68, 4, 70, 0, 72, 66, 74, 12, 76, 4, 78, 16, 81, 82, 82, 80, 64, 80, 86, 0, 88
OFFSET
1,2
FORMULA
a(n) = n - A318458(n).
MATHEMATICA
Array[# - BitAnd[#, DivisorSigma[1, #] - #] &, 100] (* Paolo Xausa, Mar 12 2024 *)
PROG
(PARI)
A318458(n) = bitand(n, sigma(n)-n);
A324648(n) = (n-A318458(n));
(PARI) A324648(n) = (n-bitand(n, sigma(n)-n));
CROSSREFS
Cf. A001065, A004198, A318458, A324658, A324649 (positions of zeros).
Sequence in context: A376908 A376339 A089886 * A071511 A119922 A097860
KEYWORD
nonn,look
AUTHOR
Antti Karttunen, Mar 14 2019
STATUS
approved