A154471 -id:A154471

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

Search: a154471 -id:a154471

Displaying 1-2 of 2 results found.

page 1

A154472

a(n) = A126309(A154471(n)).

+20
5

42, 218, 359, 875, 1763, 2359496, 926357642, 1431707647759, 239418125921492, 9138627621456887, 5265474933763866437, 36640566669911088560059, 1544449741807406472977531, 12634727265105076809694418

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,1

COMMENTS

This sequence essentially gives the iterated S-expressions of the sequence A154471, with ()'s removed. See A154473.

LINKS

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

CROSSREFS

a(n) = A080300(A154473(n)).

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jan 11 2009

STATUS

approved

A154476

Number of e's in each iteration of Wolfram's e[x_][y_] -> x[x[y]] symbolic rewriting system, starting from the initial state e[e[e][e]][e][e]

+10
3

6, 8, 8, 9, 9, 15, 20, 25, 29, 32, 37, 43, 46, 48, 50, 51, 51, 51, 52, 52, 52, 55, 56, 56, 56, 57, 57, 57, 59, 61, 62, 62, 62, 63, 63, 63, 66, 67, 67, 67, 68, 68, 68, 71, 73, 75, 76, 76, 76, 77, 77, 77, 80, 81, 81, 81, 82, 82, 82, 84, 86, 87, 87, 87, 88, 88, 88, 93, 94, 94

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,1

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(A154471(n)) - A072643(A154472(n)).

EXAMPLE

The iteration starts from the initial term e[e[e][e]][e][e], which contains 6 e's, thus a(0)=6.

CROSSREFS

a(n) = A154475(n)+1.