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 A169695 #30 Apr 17 2024 02:34:50 %S A169695 1,1,2,2,1,2,2,2,2,1,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2, %T A169695 2,2,1,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2, %U A169695 2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,1,2,2,2,2 %N A169695 a(n) = 1 if n is a square, otherwise a(n) = 2. %C A169695 Also number of central divisors of n, if n >= 1. - _Omar E. Pol_, Feb 10 2011. %C A169695 Length of n-th row in the array of A207375, if n >= 1. - _Omar E. Pol_, Feb 27 2012 %H A169695 Antti Karttunen, <a href="/A169695/b169695.txt">Table of n, a(n) for n = 0..65537</a> %H A169695 <a href="/index/Eu#epf">Index entries for sequences computed from exponents in factorization of n</a>. %F A169695 From _Omar E. Pol_, Feb 10 2011: (Start) %F A169695 a(n) = 2 - A010052(n). %F A169695 a(n) = 1 + A049240(n), n >=1. %F A169695 a(n) = A000005(n)-A161840(n), n >= 1. (End) %t A169695 Array[2 - Boole[IntegerQ@ Sqrt@ #] &, 105, 0] (* _Michael De Vlieger_, Nov 03 2017 *) %o A169695 (PARI) a(n) = 2 - issquare(n); \\ _Amiram Eldar_, Apr 17 2024 %Y A169695 Cf. A010052, A275437. %Y A169695 Cf. A000005, A049240, A161840. %K A169695 nonn,easy %O A169695 0,3 %A A169695 _N. J. A. Sloane_, Apr 15 2010