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

1,2

Links

Table of n, a(n) for n=1..32.

Formula

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

Maple

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

Prog

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

Crossrefs

Cf. A128444.

Sequence in context: A273490 A324221 A177206 * A245470 A135854 A221905

Adjacent sequences: A128440 A128441 A128442 * A128444 A128445 A128446

Keyword

nonn,easy

Author

Clark Kimberling, Mar 03 2007

Extensions

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

Status

approved