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 A152977 Square array A(n,k), n>=0, k>=0, read by antidiagonals: A(n,k) is the number of partitions of 2^n into powers of 2 less than or equal to 2^k. 13

%I

%S 1,1,1,1,2,1,1,2,3,1,1,2,4,5,1,1,2,4,9,9,1,1,2,4,10,25,17,1,1,2,4,10,

%T 35,81,33,1,1,2,4,10,36,165,289,65,1,1,2,4,10,36,201,969,1089,129,1,1,

%U 2,4,10,36,202,1625,6545,4225,257,1,1,2,4,10,36,202,1827,17361,47905,16641,513,1

%N Square array A(n,k), n>=0, k>=0, read by antidiagonals: A(n,k) is the number of partitions of 2^n into powers of 2 less than or equal to 2^k.

%C Column sequences converge towards A002577.

%H Alois P. Heinz, <a href="/A152977/b152977.txt">Antidiagonals n = 0..140, flattened</a>

%F A(n,k) = [x^2^(n-1)] 1/(1-x) * 1/Product_{j=0..k-1} (1-x^(2^j)) for n>0; A(0,k) = 1.

%e A(3,2) = 9, because there are 9 partitions of 2^3=8 into powers of 2 less than or equal to 2^2=4: [4,4], [4,2,2], [4,2,1,1], [4,1,1,1,1], [2,2,2,2], [2,2,2,1,1], [2,2,1,1,1,1], [2,1,1,1,1,1,1], [1,1,1,1,1,1,1,1].

%e Square array A(n,k) begins:

%e 1, 1, 1, 1, 1, 1, ...

%e 1, 2, 2, 2, 2, 2, ...

%e 1, 3, 4, 4, 4, 4, ...

%e 1, 5, 9, 10, 10, 10, ...

%e 1, 9, 25, 35, 36, 36, ...

%e 1, 17, 81, 165, 201, 202, ...

%p b:= proc(n,j) local nn, r;

%p if n<0 then 0

%p elif j=0 then 1

%p elif j=1 then n+1

%p elif n<j then b(n,j):= b(n-1, j) +b(2*n, j-1)

%p else nn:= 1 +floor(n);

%p r:= n-nn;

%p (nn-j) *binomial(nn, j) *add (binomial(j, h)

%p /(nn-j+h) *b(j-h+r, j) *(-1)^h, h=0..j-1)

%p fi

%p end:

%p A:= (n,k)-> `if` (n=0, 1, b(2^(n-k), k)):

%p seq (seq (A(n, d-n), n=0..d), d=0..11);

%Y Columns k=0-10 give: A000012, A094373, A028400(n-2) for n>1, A210772, A210773, A210774, A210775, A210776, A210777, A210778, A210779.

%Y Cf. A002577, A000123, A181322, A145515.

%Y Diagonal and lower diagonals give: A002577, A125792, A125794.

%K nonn,tabl

%O 0,5

%A _Alois P. Heinz_, Jan 26 2011

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