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A342446
Square table read by antidiagonals downwards: T(n,k) = floor((4/(4^(1/2^n)-1))^(1/2^k)).
0
1, 4, 1, 9, 2, 1, 21, 3, 1, 1, 44, 4, 1, 1, 1, 90, 6, 2, 1, 1, 1, 182, 9, 2, 1, 1, 1, 1, 367, 13, 3, 1, 1, 1, 1, 1, 736, 19, 3, 1, 1, 1, 1, 1, 1, 1475, 27, 4, 1, 1, 1, 1, 1, 1, 1, 2952, 38, 5, 2, 1, 1, 1, 1, 1, 1, 1, 5907, 54, 6, 2, 1, 1, 1, 1, 1, 1, 1, 1
OFFSET
0,2
COMMENTS
Every positive integer occurs infinitely often.
LINKS
N. J. Fine and Marcin E. Kuczma, Writing Integers with Exactly Three Fours, Problem E 3363 [1990, 63], Amer. Math. Monthly, Vol. 99 (1992), No. 2, pp. 163-164.
FORMULA
T(n,k) = floor((4/(4^(1/2^n)-1))^(1/2^k)).
EXAMPLE
T(2,1) = floor((4/(4^(1/4)-1))^(1/2)) = floor(sqrt(4/(sqrt(2)-1))) = floor(3.1075...) = 3.
CROSSREFS
Sequence in context: A331151 A085383 A365539 * A306744 A304526 A333352
KEYWORD
nonn,tabl
AUTHOR
Franz Vrabec, Mar 12 2021
STATUS
approved