A300077 Decimal expansion of Pi/2 truncated to n places.

1, 15, 157, 1570, 15707, 157079, 1570796, 15707963, 157079632, 1570796326, 15707963267, 157079632679, 1570796326794, 15707963267948, 157079632679489, 1570796326794896, 15707963267948966, 157079632679489661, 1570796326794896619, 15707963267948966192

Offset: 1

Author

Martin Renner, Feb 24 2018

Keywords

• nonn
• base
• easy
• less

Crossrefs

Cf. A011545, A019669.

Programs

Maple

seq(floor(1/2*Pi*10^n),n=0..19);

Mathematica

Array[Floor[10^#*Pi/2] &, 20, 0] (* Michael De Vlieger, Feb 25 2018 *)
Module[{nn=30,pi2},pi2=RealDigits[Pi/2,10,nn][[1]];Table[FromDigits[ Take[ pi2,n]],{n,nn}]] (* Harvey P. Dale, Jan 12 2022 *)

Formula

a(n) = floor((1/2)*Pi*10^n), Pi = 3.14159265...