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

1,1

Links

Table of n, a(n) for n=1..15.

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

Example

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.

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}]]

Prog

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

Crossrefs

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

Sequence in context: A321426 A281566 A271637 * A337162 A281690 A201141

Adjacent sequences: A249123 A249124 A249125 * A249127 A249128 A249129

Keyword

nonn,base

Author

Harvey P. Dale, Oct 21 2014

Status

approved