A176777 a(n) = 2^n-n*(n-3).

1, 4, 6, 8, 12, 22, 46, 100, 216, 458, 954, 1960, 3988, 8062, 16230, 32588, 65328, 130834, 261874, 523984, 1048236, 2096774, 4193886, 8388148, 16776712, 33553882, 67108266, 134217080, 268434756, 536870158, 1073741014, 2147482780

Offset

0,2

Links

Table of n, a(n) for n=0..31.

Index entries for linear recurrences with constant coefficients, signature (5,-9,7,-2).

Formula

a(n) = +5*a(n-1) -9*a(n-2) +7*a(n-3) -2*a(n-4).

G.f.: ( 1-x-5*x^2+7*x^3 ) / ( (2*x-1)*(x-1)^3 ).

Mathematica

Table[2^n-n*(n-3), {n, 0, 5!}]

Crossrefs

Cf. A142974, A176776.

Sequence in context: A146528 A345016 A216051 * A318761 A020153 A307866

Adjacent sequences: A176774 A176775 A176776 * A176778 A176779 A176780

Keyword

nonn,easy

Author

Vladimir Joseph Stephan Orlovsky, Apr 25 2010

Extensions

Offset corrected by R. J. Mathar, Apr 28 2010

Status

approved