This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A182103 #17 Jul 22 2025 08:43:02
%S A182103 0,2,4,3,34,2,874,25,727,20,4037914,23,522956314,620,35382,40321,
%T A182103 22324392524314,715,6780385526348314,39623,439408062,3301820,
%U A182103 1177652997443428940314,40297,2432903315854636921,442386620,6402373706090881,475412423
%N A182103 Integral of exp(-x)*Phi_n(x) from 0 to infinity, Phi_n the n-th cyclotomic polynomial.
%C A182103 Appears to be all positive integers for n>1, suggesting the possibility of a combinatorial interpretation.
%H A182103 Jair Taylor, <a href="/A182103/b182103.txt">Table of n, a(n) for n = 1..497</a>
%t A182103 Table[Integrate[Cyclotomic[n, x]/Exp[x], {x, 0, Infinity}], {n, 1, 20}] (* _Vaclav Kotesovec_, Mar 01 2020 *)
%o A182103 (Sage)
%o A182103 for n in range(1, 40):
%o A182103 print(integral(e^(-x)*cyclotomic_polynomial(n),x,0,infinity))
%Y A182103 Agrees with A003422(p) for p prime.
%K A182103 nonn
%O A182103 1,2
%A A182103 _Jair Taylor_, Apr 11 2012