A095902 Number of odd entries in A004001 that are <= 2^n.

1, 2, 2, 3, 6, 12, 27, 55, 115, 235, 490, 994, 2008, 4036, 8120, 16280, 32640, 65344, 130879, 261935, 524057, 1048301, 2096855, 4193951, 8388239, 16776799, 33554339, 67109539, 134220995

Offset: 0

Author

Robert G. Wilson v, Jun 12 2004

Keywords

• more
• nonn

Comments

Even entries and odd entries are equal only when n=4, 6 and 12. Past that, the evens outnumber the odds.

Crossrefs

Cf. A000079, A004001, A095901, A283480.

Programs

Mathematica

a[1] = a[2] = 1; a[n_] := a[n] = a[a[n - 1]] + a[n - a[n - 1]]; c = 0; k = 1; Do[ While[k <= 2^n, If[ Mod[ a[k], 2] == 1, c++ ]; k++ ]; Print[c], {n, 21}]

Scheme

(define (A095902 n) (A283480 (A000079 n))) ;; Antti Karttunen, Mar 21 2017

Formula

a(n) = A283480(2^n) - Antti Karttunen, Mar 21 2017

Extensions

a(22)-a(28) from Donovan Johnson, Jan 28 2009