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A205493 Third row or column of table A205497. 1
1, 14, 109, 623, 2951, 12331, 47191, 169416, 579889, 1914226, 6144668, 19298724, 59579803, 181448918, 546629054, 1632497850, 4841448042, 14277423006, 41912838982, 122587133760, 357476552161, 1039922075888, 3019280091491, 8752184436454, 25337900299765 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
See A205497 regarding association of this sequence with generating functions for the rows of the tabular form of A050446.
LINKS
FORMULA
Conjecture 1. a(n) = M_{n,3} = M_{3,n}, where M = A205497.
Conjecture 2. Let w=2*cos(Pi/9). Then lim_{n -> infinity) a(n+1)/a(n) = w^3-2*w = spectral radius of the 4 X 4 unit-primitive matrix (see [Jeffery]) A_{9,3} = [0,0,0,1; 0,0,1,1; 0,1,1,1; 1,1,1,1].
PROG
(Python) # See program in A205497.
CROSSREFS
Sequence in context: A020327 A039629 A349296 * A074886 A294445 A036395
KEYWORD
nonn
AUTHOR
L. Edson Jeffery, Jan 28 2012
EXTENSIONS
a(24) and changed title from Hugo Pfoertner, Jan 05 2020
STATUS
approved

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Last modified March 28 16:28 EDT 2024. Contains 371254 sequences. (Running on oeis4.)