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 A284009 #12 Mar 23 2017 14:40:27
%S A284009 1,2,2,3,4,4,3,4,5,5,6,6,6,6,4,5,6,6,8,9,10,9,8,8,8,8,9,9,8,8,5,6,7,7,
%T A284009 10,10,13,13,11,12,13,12,15,16,14,13,10,10,10,10,13,14,15,14,12,12,11,
%U A284009 11,12,12,10,10,6,7,8,8,12,12,15,15,14,15,17,17,20,21,20,19,14,15,16,15,21,22,24,24,20,21,20,18,21,21,17,17,12,12,12,12,17,18
%N A284009 Number of primes (counted with multiplicity) dividing lcm(A260443(n), A260443(n+1)): a(n) = A001222(A284008(n)).
%H A284009 Antti Karttunen, <a href="/A284009/b284009.txt">Table of n, a(n) for n = 0..8191</a>
%F A284009 a(n) = A001222(A284008(n)).
%F A284009 Other identities. For all n >= 0:
%F A284009 a(n) + A277328(n) = A007306(1+n).
%t A284009 a[p_?PrimeQ] := a[p] = Prime[ PrimePi[p] + 1]; a[1] = 1; a[n_] := a[n] = Times @@ ( a[First[#]] ^ Last[#] & ) /@ FactorInteger[n]; (* after _Jean-François Alcover_, in A003961 *) A[n_]:= If[n<2, n + 1, If[EvenQ[n], a[A[n/2]], A[(n - 1)/2] A[(n + 1)/2]]] ;Table[A[n], {n, 0, 51}] (* sequence A260443 *) Table[PrimeOmega[LCM[A[n], A[n + 1]]], {n, 0, 101}] (* _Indranil Ghosh_, Mar 22 2017 *)
%o A284009 (PARI)
%o A284009 A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ From _Michel Marcus_
%o A284009 A260443(n) = if(n<2, n+1, if(n%2, A260443(n\2)*A260443(n\2+1), A003961(A260443(n\2))));
%o A284009 A284008(n) = lcm(A260443(n),A260443(1+n));
%o A284009 A284009(n) = bigomega(A284008(n));
%o A284009 (Scheme) (define (A284009 n) (A001222 (A284008 n)))
%Y A284009 Cf. A001222, A007306, A277328, A284008.
%K A284009 nonn,look
%O A284009 0,2
%A A284009 _Antti Karttunen_, Mar 22 2017