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 A334954 #50 Jan 06 2022 05:17:08 %S A334954 2,3,3,4,3,5,3,5,4,5,3,7,3,5,5,6,3,7,3,7,5,5,3,9,4,5,5,7,3,9,3,7,5,5, %T A334954 5,10,3,5,5,9,3,9,3,7,7,5,3,11,4,7,5,7,3,9,5,9,5,5,3,13,3,5,7,8,5,9,3, %U A334954 7,5,9,3,13,3,5,7,7,5,9,3,11,6,5,3,13,5,5,5,9,3,13,5,7,5,5,5,13,3,7,7,10,3,9,3,9 %N A334954 a(n) is 1 plus the number of divisors of n. %C A334954 a(n) is the number of times that every divisor of n occurs in the coordinates of divisors of n mentioned in A337360 (Corneth). %C A334954 a(n) = 3 if and only if n is prime. %C A334954 a(n) is even if and only if n is a square. %C A334954 a(n) is the number of characteristic subgroups of the dihedral group D_2n. - _Firdous Ahmad Mala_, Dec 25 2021 %H A334954 David A. Corneth, <a href="/A334954/b334954.txt">Table of n, a(n) for n = 1..10000</a> %F A334954 a(n) = 1 + A000005(n). %F A334954 a(n) = A337360(n)/A000203(n). %F A334954 a(n) = A212356(n) for n >= 3. - _Ilya Gutkovskiy_, Aug 27 2020 %t A334954 1 + DivisorSigma[0, Range[105]] (* _Michael De Vlieger_, Sep 11 2020 *) %o A334954 (PARI) a(n) = numdiv(n) + 1 %Y A334954 Partial sums give A156745. %Y A334954 Cf. A000005, A088580, A000203, A212356, A337360. %K A334954 nonn,easy %O A334954 1,1 %A A334954 _David A. Corneth_ and _Omar E. Pol_, Aug 25 2020