A249126 Product of the first n digits of Pi (treated as a number) and the first n digits of e (treated as a number).

6, 837, 85094, 8537238, 853922530, 85397212652, 8539729843352, 853973398759468, 85397341863406230, 8539734219628209684, 853973422224398765940, 85397342226185298383510, 8539734222671268708689351, 853973422267317150596927230, 85397342226735418150399772016

Offset: 1

Author

Harvey P. Dale, Oct 21 2014

Keywords

• nonn
• base

Examples

			The first digit of Pi is 3, the first digit of e is 2, and 2 times 3 = 6, so a(1) = 6.  The first two digits of Pi are 31, the first two digits of e are 27, and 31 times 27 = 837, so a(2) = 837.
		

Crossrefs

Cf. A011543 (e), A011545 (Pi).

Programs

Mathematica

Module[{nn=20,p,e},p=RealDigits[Pi,10,nn][[1]];e=RealDigits[E,10,nn][[1]];Table[FromDigits[Take[p,n]]FromDigits[Take[e,n]],{n,nn}]]

PARI

a(n)=n--; floor(10^n * Pi) * floor(10^n * exp(1)) \\ Charles R Greathouse IV, Oct 21 2014

Formula

a(n+1) = floor(10^n * Pi) * floor(10^n * e). - Charles R Greathouse IV, Oct 21 2014

a(n) ~ Pi*e/100 * 100^n + O(10^n). - Charles R Greathouse IV, Oct 21 2014

a(n) = A011543(n-1)*A011545(n-1). - Michel Marcus, Oct 26 2014