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 A065899 #26 Jun 02 2021 22:38:16
%S A065899 1,14,148,1458,15293,188782,2692726,40909988,660637057,11976280879,
%T A065899 240871231369,5080851687840,112183659405198,2700581280109040,
%U A065899 67686358108129808,1763651979163805444,47707175694652299653,1337959106215345951164,40196133912310028013721,1287910861213828031657392
%N A065899 a(n) is the index of the n-th compositorial number, A036691(n), in the sequence of composites (A002808).
%F A065899 a(n) = A036691(n) - primepi(A036691(n))-1.
%F A065899 a(n) = A065855(A036691(n)). - _Chai Wah Wu_, Sep 08 2020
%e A065899 a(2) = 14 because 4*6 = 24, the 2nd compositorial number is the 14th composite number: 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 22, 24.
%t A065899 Table[A036691[n]-(PrimePi[A036691[n]])-1, {n, 1, 9}]
%t A065899 Composite[n_] := FixedPoint[n + PrimePi[ # ] + 1 &, n + PrimePi[n] + 1]; Table[c = Product[ Composite[i], {i, 1, n} ]; c - PrimePi[c] - 1, {n, 1, 10} ]
%o A065899 (Python)
%o A065899 from sympy import factorial, primepi, composite, primorial, compositepi
%o A065899 def A065899(n):
%o A065899 return compositepi(factorial(composite(n))//primorial(primepi(composite(n)))) # _Chai Wah Wu_, Sep 08 2020
%Y A065899 Cf. A002808, A000720, A036691, A065855.
%K A065899 nonn
%O A065899 1,2
%A A065899 _Labos Elemer_, Nov 28 2001
%E A065899 One more term from _Robert G. Wilson v_, Nov 29 2001
%E A065899 a(11)-a(19) from _Chai Wah Wu_, Sep 08 2020
%E A065899 a(20) from _Chai Wah Wu_, Sep 09 2020
%E A065899 Name rewritten by _Felix Fröhlich_, Jun 01 2021