A154475 Number of opening (equally: closing) brackets in each term of Wolfram's Symbolic Rewriting system A154473-A154474.

5, 7, 7, 8, 8, 14, 19, 24, 28, 31, 36, 42, 45, 47, 49, 50, 50, 50, 51, 51, 51, 54, 55, 55, 55, 56, 56, 56, 58, 60, 61, 61, 61, 62, 62, 62, 65, 66, 66, 66, 67, 67, 67, 70, 72, 74, 75, 75, 75, 76, 76, 76, 79, 80, 80, 80, 81, 81, 81, 83, 85, 86, 86, 86, 87, 87, 87, 92, 93, 93

Offset

0,1

Comments

2*a(n) gives the number of bits in A154474(n).

Links

A. Karttunen, Table of n, a(n) for n = 0..100

S. Wolfram, A New Kind of Science, Wolfram Media Inc., (2002), p. 102, p. 103 and pages 104, 896-898.

Formula

a(n) = A072643(A154472(n)).

Example

The iteration starts from the initial term e[e[e][e]][e][e], which contains 5 ['s (and also 5 ]'s), thus a(0)=5.

Crossrefs

a(n) = A029837(1+A154473(n))/2. a(n) = A154476(n)-1.

Sequence in context: A114916 A001989 A086056 * A375336 A264527 A137755

Adjacent sequences: A154472 A154473 A154474 * A154476 A154477 A154478

Keyword

nonn

Author

Antti Karttunen, Jan 11 2009

Status

approved