# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/

Search: id:a374668
Showing 1-1 of 1

%I A374668 #10 Jul 19 2024 14:25:41
%S A374668 1,1,31,10254,12238276,41596930860,309346186680924,
%T A374668 4522151204857137264,116038936382978521700928,
%U A374668 4918677318766771695942334272,323424014903141386787887115413440,31725978444319999354629697685162941056,4460612938377274751881312432310360618154240
%N A374668 a(n) is the permanent of the n-th order Hankel matrix M whose generic element is given by M(i,j) = A317614(i+j-1) with i,j = 1, ..., n.
%C A374668 The Hankel transform of A317614 has the following polynomial as g.f. 1 + x - x^2 - 624*x^3 - 9216*x^4 + 138240*x^5 - 331776*x^6: the matrices are singular for n > 6.
%H A374668 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>.
%e A374668 a(7) = 4522151204857137264:
%e A374668   [  1,   4,  15,  32,  65, 108,  175]
%e A374668   [  4,  15,  32,  65, 108, 175,  256]
%e A374668   [ 15,  32,  65, 108, 175, 256,  369]
%e A374668   [ 32,  65, 108, 175, 256, 369,  500]
%e A374668   [ 65, 108, 175, 256, 369, 500,  671]
%e A374668   [108, 175, 256, 369, 500, 671,  864]
%e A374668   [175, 256, 369, 500, 671, 864, 1105]
%e A374668 which is the singular matrix M of minimal order.
%t A374668 A317614[n_]:=(1/2)*(n^3 + n*Mod[n,2]); a[n_]:=Permanent[Table[A317614[i+j-1], {i, n}, {j, n}]]; Join[{1}, Array[a, 12]]
%Y A374668 Cf. A317614.
%Y A374668 Cf. A000583 (trace of M), A006010 (sum of the 1st row or column of M), A035287 (super- or subdiagonal sum of M), A346174, A374708 (k-th super- or subdiagonal sum of M).
%K A374668 nonn
%O A374668 0,3
%A A374668 _Stefano Spezia_, Jul 15 2024

# Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE