A257808 a(n) = number of nonzero even numbers in range 0 .. n of A233271, the infinite trunk of inverted binary beanstalk.

0, 0, 1, 2, 2, 3, 4, 4, 5, 5, 6, 7, 7, 8, 9, 10, 11, 11, 11, 12, 13, 13, 14, 14, 14, 14, 15, 15, 16, 17, 17, 18, 19, 20, 20, 20, 21, 22, 22, 23, 24, 24, 24, 25, 26, 27, 28, 29, 30, 30, 31, 32, 32, 32, 32, 32, 33, 33, 34, 35, 35, 36, 37, 38, 38, 38, 39, 40, 40, 41, 41, 42, 43, 43, 43, 43, 43, 43, 44, 45, 46, 46, 46, 46, 47, 48, 49, 50, 51

Offset: 0

Author

Antti Karttunen, May 12 2015

Keywords

• nonn

Comments

a(n) = the largest number k such that A257804(k) <= n.

Links

• Antti Karttunen, Table of n, a(n) for n = 0..16405

Crossrefs

Cf. A233271, A257800, A257804, A257806, A257807.

Formula

a(0) = 0; for n >= 1, a(n) = (1-A257800(n)) + a(n-1).

Other identities. For all n >= 0:

a(n) = A257806(n) + A257807(n).

a(A257804(n)) = n. [This sequence works as a left inverse for injection A257804.]