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A224607
a(n) = A219331(n^2).
3
1, 5, 28, 269, 6181, 286790, 26808447, 5037694829, 1902773895751, 1444565587750055, 2204357811343981558, 6761166975496300074014, 41682712965722542326438411, 516517498759950258411494666787, 12864972023450485679400300069493738
OFFSET
1,2
COMMENTS
A219331 is the logarithmic derivative of A006456, where A006456(n) is the number of compositions of n into sums of squares.
FORMULA
Logarithmic derivative of A224608.
EXAMPLE
L.g.f.: L(x) = x + 5*x^2/2 + 28*x^3/3 + 269*x^4/4 + 6181*x^5/5 + 286790*x^6/6 +...
where
exp(L(x)) = 1 + x + 3*x^2 + 12*x^3 + 81*x^4 + 1335*x^5 + 49309*x^6 + 3882180*x^7 +...+ A224608(n)*x^n +...
PROG
(PARI) {a(n)=n^2*polcoeff(-log(1-sum(r=1, n, x^(r^2)+x*O(x^(n^2)))), n^2)}
for(n=1, 30, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Apr 12 2013
STATUS
approved