A318468 a(n) = 2*n AND A000203(n), where AND is bitwise-and (A004198) and A000203 = sum of divisors.

0, 0, 4, 0, 2, 12, 8, 0, 0, 16, 4, 24, 10, 24, 24, 0, 2, 36, 4, 40, 32, 36, 8, 48, 18, 32, 32, 56, 26, 8, 32, 0, 0, 4, 0, 72, 2, 12, 8, 80, 2, 64, 4, 80, 74, 72, 16, 96, 32, 68, 64, 96, 34, 104, 72, 112, 80, 80, 52, 40, 58, 96, 104, 0, 0, 128, 4, 8, 0, 128, 8, 128, 2, 16, 20, 136, 0, 136, 16, 160, 32, 36, 4, 160, 40, 132, 40, 176, 18, 160, 48

Offset

1,3

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for sequences related to binary expansion of n

Index entries for sequences related to sigma(n)

Formula

a(n) = A004198(2*n, A000203(n)).

a(n) = A224880(n) - A318466(n) = (A224880(n)-A318467(n))/2.

Mathematica

Array[BitAnd[2 #, DivisorSigma[1, #]] &, 91] (* Michael De Vlieger, Apr 21 2019 *)

Prog

(PARI) A318468(n) = bitand(2*n, sigma(n));

Crossrefs

Cf. A000203, A003987, A318466, A318467.

Cf. also A318458.

Sequence in context: A279413 A208748 A134895 * A346492 A145877 A373984

Adjacent sequences: A318465 A318466 A318467 * A318469 A318470 A318471

Keyword

nonn,base

Author

Antti Karttunen, Aug 26 2018

Status

approved