A276162 Square array read by antidiagonals: T(n,k) = Product_{i = 1..k} gcd(n, i).

1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 2, 3, 4, 1, 1, 1, 2, 3, 4, 1, 1, 2, 1, 8, 3, 8, 1, 1, 1, 6, 1, 8, 9, 8, 1, 1, 2, 1, 12, 5, 16, 9, 16, 1, 1, 1, 2, 1, 12, 5, 16, 9, 16, 1, 1, 2, 3, 8, 1, 72, 5, 64, 27, 32, 1, 1, 1, 2, 3, 8, 1, 72, 5, 64, 27, 32, 1, 1, 2, 1, 4

Offset: 1

Author

Peter Kagey, Aug 22 2016

Keywords

• nonn
• tabl

Examples

			T(6, 3) = gcd(6, 1) * gcd(6, 2) * gcd(6, 3) = 6.
		

Links

• Peter Kagey, Table of n, a(n) for n = 1..10000
• Mohamed Abobakr, Greatest common divisor sequence

Crossrefs

Cf. A051190, A067911, A092287.

Programs

Haskell

a276162T n k = product $ map (gcd n) [1..k]
-- Peter Kagey, Aug 23 2016

PARI

T(n,k)=prod(i=2,k,gcd(n,i))
for(s=1,15,for(k=1,s-1, print1(T(s-k,k)", "))) \\ Charles R Greathouse IV, Aug 22 2016