login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Numerator of floor(e*10^n)/10^n, where e = exp(1) = A001113.
1

%I #15 Jan 27 2022 21:59:16

%S 2,27,271,1359,13591,67957,2718281,13591409,135914091,679570457,

%T 6795704571,54365636569,2718281828459,2718281828459,16989261427869,

%U 543656365691809,6795704571147613,271828182845904523,543656365691809047,27182818284590452353

%N Numerator of floor(e*10^n)/10^n, where e = exp(1) = A001113.

%C Numerator of the decimal fraction of e = 2.71828... truncated to a given number of decimal places.

%e a(2) = 271 is the numerator of 2.71 = 271/100.

%e a(3) = 1359 is the numerator of 2.718 = 2718/1000 = 1359/500.

%t Module[{nn=30,ee},ee=RealDigits[E,10,nn][[1]];Join[{2},Rest[ Numerator[ Table[ FromDigits[Take[ee,n]]/10^n,{n,nn}]]]]] (* _Harvey P. Dale_, May 15 2015 *)

%o (PARI) a(n,c=exp(1))=numerator(c\.1^n/10^n) \\ _M. F. Hasler_, Sep 21 2011

%K nonn,base

%O 0,1

%A _M. F. Hasler_, following a suggestion by _Eric Angelini_, Sep 21 2011