A027438 Largest prime factor of [e*2^n].

2, 5, 5, 7, 43, 43, 173, 347, 139, 107, 23, 293, 293, 293, 293, 293, 79, 79, 883, 883, 114013, 114013, 114013, 114013, 1232573, 1232573, 1499, 364841611, 364841611, 364841611, 364841611, 170801, 170801, 56812319, 56812319, 56812319, 56812319

Offset

0,1

Links

Sean A. Irvine, Table of n, a(n) for n = 0..360

Mathematica

Table[FactorInteger[Floor[E 2^n]][[-1, 1]], {n, 0, 40}] (* Harvey P. Dale, May 31 2013 *)

Prog

(PARI) for(n=0, 22, print(factor(floor(exp(1)*2^n))))
(Magma) [Max(PrimeDivisors(Floor(Exp(1)*2^n))):n in [0..37]]; // Marius A. Burtea, Nov 05 2019

Crossrefs

Cf. A006530, A027437.

Sequence in context: A165898 A194531 A092394 * A334388 A204237 A153162

Adjacent sequences: A027435 A027436 A027437 * A027439 A027440 A027441

Keyword

nonn

Author

N. J. A. Sloane, Allan C. Wechsler

Extensions

More terms from Jason Earls, Jul 11 2001

Status

approved