A093910 Product of n-th row of irregular triangle defined in A093911.

1, 6, 120, 5040, 5765760, 19275223968000, 13644281345408020027550269440000, 4402827357584746886229433170489943024971625310770489684257669120000000000

Offset: 1

Author

Amarnath Murthy, Apr 24 2004

Keywords

• nonn
• easy
• less

Comments

Next term has 168 digits.

Examples

			a(3) = 120 because a(1) is the product of 1 successive numbers starting with 1 = 1, and a(2) is the product of 2 successive numbers (2,3) = 6 and a(3) is the product of 3 successive numbers (4,5,6) = 120. All the products have the property that a(n) = 0 (mod a(n - 1)). Thus a(3) = 120.
		

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..11 (Term 11 has 824 decimal digits.)

Crossrefs

Cf. A090904, A093911.

Programs

Mathematica

a = {{1, 1}, {2, 2}}; Do[k = Last@ a[[i - 1]]; While[! Divisible[Pochhammer[Total@ a[[i - 1]], k], Pochhammer @@ a[[i - 1]]], k++]; AppendTo[a, {Total@ a[[i - 1]], k}], {i, 3, 8}]; Pochhammer @@ # & /@ a (* Michael De Vlieger, Dec 15 2016 *)

Formula

For n > 1, a(n) = prod_{i = A093911(n)..A093911(n+1)-1} i.

Extensions

Edited and extended by David Wasserman, Mar 27 2006

New name from Ivan Neretin, Dec 15 2016