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 A081707 #36 May 30 2020 11:15:05
%S A081707 1,1,1,1,1,2,1,1,1,2,1,3,1,2,2,1,1,3,1,3,2,2,1,4,1,2,1,3,1,5,1,1,2,2,
%T A081707 2,5,1,2,2,4,1,5,1,3,3,2,1,5,1,3,2,3,1,4,2,4,2,2,1,8,1,2,3,1,2,5,1,3,
%U A081707 2,5,1,7,1,2,3,3,2,5,1,5,1,2,1,8,2,2,2,4,1,8,2,3,2,2,2,6,1,3,3,5,1,5,1,4,5
%N A081707 a(n) = tau(n) - bigomega(n) = A000005(n) - A001222(n).
%C A081707 Number of divisors of n that are not positive powers of primes (cf. A000961). - _Benoit Cloitre_, May 03 2003; corrected Dec 16 2008 at the suggestion of _Ray Chandler_.
%C A081707 a(n) = 1 iff n is in A000961. - _Robert Israel_, Nov 23 2015
%C A081707 a(n) = 2 iff n is in A006881. - _Altug Alkan_, Nov 23 2015
%C A081707 a(n) = 3 iff n is in A054753. - _Michel Marcus_, Nov 24 2015
%H A081707 Robert Israel, <a href="/A081707/b081707.txt">Table of n, a(n) for n = 1..10000</a>
%e A081707 After first statement in comment section, a(60) = 8 because we have: 1,6,10,12,15,20,30,60. The divisors 2,3,4,5 are excluded from the count. - _Geoffrey Critzer_, Nov 22 2015
%p A081707 seq(numtheory:-tau(n)-numtheory:-bigomega(n), n=1..300); # _Robert Israel_, Nov 23 2015
%t A081707 Table[DivisorSigma[0, n] - PrimeOmega[n], {n, 1, 105}] (* _Geoffrey Critzer_, Nov 22 2015 *)
%o A081707 (PARI) first(m)=vector(m,n,numdiv(n) - bigomega(n)) \\ _Anders Hellström_, Nov 22 2015
%Y A081707 Cf. A033273(n) = tau(n) - omega(n) = A000005(n) - A001221(n).
%Y A081707 Cf. A000961.
%K A081707 nonn
%O A081707 1,6
%A A081707 _Vladeta Jovovic_, Apr 03 2003