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Triangle read by rows, 1 <= m <= n: t(n,m) = gcd(s(n,m), S(n,m)), where s(n,m) is an unsigned Stirling number of the first kind and S(n,m) is a Stirling number of the second kind.
1

%I #15 Aug 02 2019 19:24:50

%S 1,1,1,1,3,1,1,1,6,1,1,5,5,10,1,1,1,45,5,15,1,1,63,7,35,35,21,1,1,1,

%T 14,7,70,14,28,1,1,3,1,42,21,378,42,36,1,1,1,30,5,14175,21,210,30,45,

%U 1,1,33,11,2750,110,231,231,330,165,55,1,1,1,198,11,3630,11,462,33,1485,55,66,1

%N Triangle read by rows, 1 <= m <= n: t(n,m) = gcd(s(n,m), S(n,m)), where s(n,m) is an unsigned Stirling number of the first kind and S(n,m) is a Stirling number of the second kind.

%H Robert Israel, <a href="/A126799/b126799.txt">Table of n, a(n) for n = 1..10011</a> (rows 1 to 141, flattened)

%e Triangle starts:

%e 1;

%e 1, 1;

%e 1, 3, 1;

%e 1, 1, 6, 1;

%e 1, 5, 5, 10, 1;

%e 1, 1, 45, 5, 15, 1;

%p with(combinat): T:=(n,k)->gcd(abs(stirling1(n,k)),stirling2(n,k)): for n from 1 to 13 do seq(T(n,k),k=1..n) od; # yields sequence in triangular form - _Emeric Deutsch_, Feb 25 2007

%Y Cf. A008275, A008277, A128266 (row sums).

%K nonn,tabl

%O 1,5

%A _Leroy Quet_, Feb 21 2007

%E More terms from _Emeric Deutsch_, Feb 25 2007