A217716 Duplicate of A129824.

2, 4, 12, 64, 700, 17424, 1053696, 160579584, 62856336636, 63812936890000, 168895157342195152, 1169048914836855865344, 21209591746609937928524800, 1010490883477487017627972550656, 126641164340871500483202065902080000

Offset

0,1

Comments

Number of words less than or equal to the concatenation of the n-th row of Pascal's Triangle.

a(n) = 2 * A055612(n). - Reinhard Zumkeller, Jan 31 2015

Same as A129824. - Georg Fischer, Oct 14 2018

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..69

Formula

a(n) = Product_{k=0..n} (binomial(n,k) + 1).

Example

Row 2 is 1 2 1 and we have 000, 001, 010, 011, 020, 021, 100, 101, 110, 111, 120 and 121 so a(2)=12.

Mathematica

Table[Product[Binomial[n, k] + 1, {k, 0, n}], {n, 0, 15}] (* T. D. Noe, Mar 21 2013 *)

Crossrefs

Sequence in context: A005831 A136512 A137160 * A129824 A266463 A013207

Adjacent sequences: A217713 A217714 A217715 * A217717 A217718 A217719

Keyword

dead

Author

Jon Perry, Mar 21 2013

Status

approved