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a(n) = floor( e * 2^n ).
6

%I #29 Apr 07 2021 19:22:00

%S 2,5,10,21,43,86,173,347,695,1391,2783,5567,11134,22268,44536,89072,

%T 178145,356290,712581,1425162,2850325,5700650,11401300,22802600,

%U 45605201,91210402,182420805,364841611,729683222,1459366444,2918732888,5837465777,11674931554

%N a(n) = floor( e * 2^n ).

%C Parity gives A004593 (expansion of e in base 2). - _Jeremy Gardiner_, Nov 03 2020.

%t Floor[E 2^Range[0,30]] (* _Harvey P. Dale_, May 19 2019 *)

%o (PARI) a(n) = floor(exp(1)*2^n) \\ _Michel Marcus_, Jul 12 2013

%Y Cf. A001113, A027438 (largest prime factor of [e*2^n]).

%K nonn

%O 0,1

%A _N. J. A. Sloane_, _Allan C. Wechsler_

%E a(28)-a(32) from _Robert Price_, Apr 07 2021