A086352 Main diagonal of square array A086350.

1, 2, 10, 74, 740, 9354, 143144, 2573586, 53180944, 1242078802, 32358633632, 930370449370, 29264294868544, 999646208968666, 36852747307934336, 1458402092927302178, 61665517131334975744, 2774522039432235946914

Offset: 0

Author

Paul Barry, Jul 18 2003

Keywords

• easy
• nonn

Crossrefs

Cf. A000169, A086350.

Formula

a(n) = ((1+sqrt(2))*(n+sqrt(2))^n-(1-sqrt(2))*(n-sqrt(2))^n)/sqrt(8).