A262518 Even bisection of A155043.

0, 1, 2, 2, 3, 3, 3, 4, 5, 4, 5, 5, 6, 6, 6, 6, 7, 7, 10, 8, 8, 8, 9, 9, 9, 10, 10, 10, 10, 11, 10, 12, 19, 12, 13, 13, 11, 14, 14, 14, 14, 15, 12, 16, 15, 15, 17, 16, 13, 18, 19, 17, 14, 18, 14, 18, 18, 19, 19, 20, 15, 21, 21, 20, 16, 22, 16, 23, 17, 23, 17, 24, 24, 25, 25, 24, 25, 26, 25, 27, 26, 26, 28, 27, 26, 27, 28, 28, 28, 29, 27, 29, 29

Offset

0,3

Comments

Number of steps needed to reach zero when starting from k = 2*n and repeatedly applying the map that replaces k by k - d(k), where d(k) is the number of divisors of k (A000005).

Links

Antti Karttunen, Table of n, a(n) for n = 0..10000

Formula

a(n) = A155043(2*n).

Prog

(Scheme) (define (A262518 n) (A155043 (+ n n)))

Crossrefs

Cf. A000005, A049820, A155043, A262519, A262520, A262682.

Sequence in context: A194311 A134403 A124882 * A085578 A350066 A360917

Adjacent sequences: A262515 A262516 A262517 * A262519 A262520 A262521

Keyword

nonn

Author

Antti Karttunen, Oct 02 2015

Status

approved