A128443 a(n) = floor(n*3^(n/2)).

1, 6, 15, 36, 77, 162, 327, 648, 1262, 2430, 4629, 8748, 16414, 30618, 56819, 104976, 193187, 354294, 647747, 1180980, 2147793, 3897234, 7057034, 12754584, 23012070, 41452398, 74559107, 133923132, 240246014, 430467210, 770444114, 1377495072

Offset: 1

Author

Clark Kimberling, Mar 03 2007

Keywords

• nonn
• easy

Crossrefs

Cf. A128444.

Programs

Maple

seq(floor(evalf(n*3^(n/2))), n=1..32); # Georg Fischer, Aug 31 2021

PARI

a(n) = sqrtint(n^2*3^n); \\ Michel Marcus, Aug 31 2021

Formula

a(n) = A128444(n,n).

Extensions

a(24) and more terms corrected by Georg Fischer, Aug 31 2021