A250973
T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with no 2X2 subblock having the sum of its diagonal elements less than the absolute difference of its antidiagonal elements.
Original entry on oeis.org
14, 49, 49, 172, 308, 172, 604, 1945, 1945, 604, 2121, 12281, 22048, 12281, 2121, 7448, 77537, 249921, 249921, 77537, 7448, 26154, 489543, 2833397, 5089900, 2833397, 489543, 26154, 91841, 3090834, 32124018, 103684186, 103684186, 32124018
Offset: 1
Some solutions for n=3 k=4
..0..0..0..0..1....0..0..0..1..1....0..1..0..0..0....0..0..0..1..0
..0..0..0..1..1....0..1..1..0..0....0..1..1..1..1....1..1..1..0..1
..1..1..1..0..1....1..1..0..1..1....0..1..0..0..0....1..1..0..1..0
..1..1..0..1..1....0..0..1..1..0....1..1..0..0..0....0..1..0..1..1
A277084
Pisot sequence L(4,14).
Original entry on oeis.org
4, 14, 49, 172, 604, 2122, 7456, 26198, 92052, 323444, 1136489, 3993295, 14031289, 49301911, 173232725, 608689936, 2138761243, 7514991434, 26405516950, 92781386582, 326007088306, 1145495077635, 4024940008834, 14142480741305, 49692606865991, 174605518105877
Offset: 0
Cf.
A008776 for definitions of Pisot sequences.
Cf.
A010904 (Pisot sequence E(4,14)),
A251221 (seems to be Pisot sequence P(4,14)).
-
RecurrenceTable[{a[0] == 4, a[1] == 14, a[n] == Ceiling[a[n - 1]^2/a[n - 2]]}, a, {n, 25}]
A278692
Pisot sequence T(4,14).
Original entry on oeis.org
4, 14, 49, 171, 596, 2077, 7238, 25223, 87897, 306303, 1067403, 3719680, 12962320, 45171020, 157411717, 548547468, 1911575138, 6661446313, 23213770727, 80895217952, 281903201529, 982374694626, 3423373822671, 11929753885009, 41572739387791, 144872448909191, 504850696923520, 1759300875378480
Offset: 0
Cf.
A008776 for definitions of Pisot sequences.
Cf.
A010904 (Pisot sequence E(4,14)),
A251221 (seems to be Pisot sequence P(4,14)),
A277084 (Pisot sequence L(4,14)).
-
RecurrenceTable[{a[0] == 4, a[1] == 14, a[n] == Floor[a[n - 1]^2/a[n - 2]]}, a, {n, 27}]
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first(n)=my(v=vector(n+1)); v[1]=4; v[2]=14; for(i=3,#v, v[i]=v[i-1]^2\v[i-2]); v \\ Charles R Greathouse IV, Nov 28 2016
-
from itertools import islice
def A278692_gen(): # generator of terms
a, b = 4, 14
yield from (a,b)
while True:
a, b = b, b**2//a
yield b
A278692_list = list(islice(A278692_gen(),30)) # Chai Wah Wu, Dec 06 2023
Showing 1-3 of 3 results.
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