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A117836 Semiprimes of the form floor(e^k). 1
403, 3269017, 485165195, 3584912846, 26489122129, 29048849665247, 639843493530054949, 114200738981568428366295718, 66631762164108958342448140502408732626873, 492345828601205839975486205911330449483779 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Giovanni Resta, Table of n, a(n) for n = 1..17

FORMULA

a(n) = {floor(e^k) = p*q for integer k, p and q prime}. a(n) = A000149 INTERSECTION A001358.

EXAMPLE

a(1) = 403 = floor(e^6) = 13 * 31.

a(2) = 3269017 = floor(e^15) = 773 * 4229.

a(3) = 485165195 = floor(e^20) = 5 * 97033039.

a(4) = 3584912846 = floor(e^22) = 2 * 1792456423.

a(5) = 26489122129 = floor(e^24) = 103 * 257175943.

CROSSREFS

Cf. A000040, A000149, A001358, A074496.

Sequence in context: A165808 A283662 A097741 * A185640 A185637 A234675

Adjacent sequences:  A117833 A117834 A117835 * A117837 A117838 A117839

KEYWORD

nonn

AUTHOR

Jonathan Vos Post, Apr 30 2006

EXTENSIONS

a(6)-a(10) from Giovanni Resta, Jun 15 2016

STATUS

approved

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Last modified February 21 05:23 EST 2020. Contains 332086 sequences. (Running on oeis4.)