|
Search: id:A113724
|
|
|
| A113724 |
|
A variant of Golomb's sequence using even numbers: a(n) is the number of times 2*n+2 occurs, starting with a(1) = 2. |
|
+0
4
|
|
| 2, 4, 4, 6, 6, 6, 6, 8, 8, 8, 8, 10, 10, 10, 10, 10, 10, 12, 12, 12, 12, 12, 12, 14, 14, 14, 14, 14, 14, 16, 16, 16, 16, 16, 16, 18, 18, 18, 18, 18, 18, 18, 18, 20, 20, 20, 20, 20, 20, 20, 20, 22, 22, 22, 22, 22, 22, 22, 22, 24, 24, 24, 24, 24, 24, 24, 24, 26, 26, 26, 26, 26, 26
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
a(n) is taken to be the smallest number >= a(n-1) which is compatible with the description.
|
|
EXAMPLE
|
Start with 2 in row 1 and form a triangle where row n is
generated from row n-1 by the rule given in the description.
Then row 2 will have (2) 4's,
row 3 will have (4) 6's and (4) 8's, etc.
The triangle begins:
2;
4,4;
6,6,6,6,8,8,8,8; ...
The number of terms in each row (also row sums with offset)
is given by A113725:
[1,2,8,56,984,87848,115679160,...].
|
|
PROGRAM
|
(PARI) a=[2, 4, 4]; for(n=2, 20, for(i=1, a[n], a=concat(a, 2*n+2))); a
|
|
CROSSREFS
|
Cf. A001462 (Golomb's sequence), A113725, A113722, A113676.
Cf. A080606. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 13 2008]
Sequence in context: A074325 A058249 A058043 this_sequence A111650 A085914 A014684
Adjacent sequences: A113721 A113722 A113723 this_sequence A113725 A113726 A113727
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Floor van Lamoen (fvlamoen(AT)hotmail.com) and Paul D. Hanna (pauldhanna(AT)juno.com), Nov 08 2005
|
|
|
Search completed in 0.002 seconds
|
