A137181 Maximal number of symbols in terms generated by an inefficient set of rewrite rules for flattening combinator expressions of initial size n.

1, 2, 4, 8, 16, 32, 273, 65569, 4294967361, 15177100720513508366558296147058741458143803430094840009779784451085189728165691939

Offset

1,2

Links

Table of n, a(n) for n=1..10.

C. Okasaki, A Spectacular Failure

Formula

a(n) = 2^(n-1), for n <= 6; a(n) = 2^a(n-3) + 2*a(n-3) + 1, for n > 6

Example

For n=6, the maximum result is generated from the initial term X (X (X (X (X X)))). For n=10, the maximum result is generated from the initial term X (X X) (X (X X) (X (X (X X)))).

Crossrefs

Sequence in context: A138814 A233424 * A272698 A355548 A036373 A119610

Adjacent sequences: A137178 A137179 A137180 * A137182 A137183 A137184

Keyword

nonn

Author

Chris Okasaki (cokasaki(AT)acm.org), Apr 04 2008

Status

approved