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A342730 a(n) = floor((frac(e*n) + 1) * prime(n+1)).

%I A342730 #20 Apr 11 2021 01:42:14
%S A342730 2,5,7,8,20,20,22,19,40,42,36,70,66,57,49,94,88,73,129,116,99,85,149,
%T A342730 135,120,197,172,149,121,206,196,165,271,236,211,172,291,256,216,175,
%U A342730 309,262,223,364,316,263,219,392,335,273,445,390,325,268,459,395
%N A342730 a(n) = floor((frac(e*n) + 1) * prime(n+1)).
%H A342730 Simon Strandgaard, <a href="/A342730/a342730.png">Plot of 400 terms</a>
%e A342730 x(n) = frac(e * n) + 1,
%e A342730 a(0) = floor(x(0) * prime(1)) = floor(1.00 *  2) =  2,
%e A342730 a(1) = floor(x(1) * prime(2)) = floor(1.72 *  3) =  5,
%e A342730 a(2) = floor(x(2) * prime(3)) = floor(1.44 *  5) =  7,
%e A342730 a(3) = floor(x(3) * prime(4)) = floor(1.15 *  7) =  8,
%e A342730 a(4) = floor(x(4) * prime(5)) = floor(1.87 * 11) = 20.
%t A342730 Array[Floor[(Mod[E #, 1] + 1) Prime[# + 1]] &, 56, 0] (* _Michael De Vlieger_, Mar 19 2021 *)
%o A342730 (Ruby) require 'prime'
%o A342730 values = []
%o A342730 primes = Prime.first(20)
%o A342730 primes.each_with_index do |prime, n|
%o A342730     x = ((n * Math::E) % 1) + 1
%o A342730     values << (x * prime).floor
%o A342730 end
%o A342730 p values
%o A342730 (PARI) a(n) = floor((frac(exp(1)*n) + 1) * prime(n+1)); \\ _Michel Marcus_, Mar 20 2021
%Y A342730 Cf. A000040, A001113.
%K A342730 nonn,look
%O A342730 0,1
%A A342730 _Simon Strandgaard_, Mar 19 2021