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 A341655 #14 Mar 04 2021 01:43:43 %S A341655 2,4,8,10,16,16,18,24,20,32,28,24,40,32,24,32,32,32,32,60,30,48,32,60, %T A341655 42,48,40,32,64,48,54,64,40,64,48,60,32,40,40,32,48,96,64,32,72,90,64, %U A341655 56,32,64,60,96,72,96,40,40,64,96,32,80,32,48,96,80,40,32 %N A341655 a(n) is the number of divisors of prime(n)^2 - 1. %C A341655 a(n) >= A309906(2) = 32 for n > 21. %F A341655 a(n) = A000005(A000040(n)^2 - 1) = A000005(A084920(n)). %e A341655 p = factorization %e A341655 n prime(n) p^2 - 1 of p^2 - 1 a(n) %e A341655 -- -------- ------- ------------------ ---- %e A341655 1 2 3 3 2 %e A341655 2 3 8 2^3 4 %e A341655 3 5 24 2^3 * 3 8 %e A341655 4 7 48 2^4 * 3 10 %e A341655 5 11 120 2^3 * 3 * 5 16 %e A341655 6 13 168 2^3 * 3 * 7 16 %e A341655 7 17 288 2^5 * 3^2 18 %e A341655 8 19 360 2^3 * 3^2 * 5 24 %e A341655 9 23 528 2^4 * 3 * 11 20 %e A341655 10 29 840 2^3 * 3 * 5 * 7 32 %e A341655 11 31 960 2^6 * 3 * 5 28 %e A341655 12 37 1368 2^3 * 3^2 * 19 24 %e A341655 13 41 1680 2^4 * 3 * 5 * 7 40 %e A341655 14 43 1848 2^3 * 3 * 7 * 11 32 %e A341655 15 47 2208 2^5 * 3 * 23 24 %e A341655 16 53 2808 2^3 * 3^3 * 13 32 %e A341655 17 59 3480 2^3 * 3 * 5 * 29 32 %e A341655 18 61 3720 2^3 * 3 * 5 * 31 32 %e A341655 19 67 4488 2^3 * 3 * 11 * 17 32 %e A341655 20 71 5040 2^4 * 3^2 * 5 * 7 60 %e A341655 21 73 5328 2^4 * 3^2 * 37 30 %e A341655 22 79 6240 2^5 * 3 * 5 * 13 48 %e A341655 23 83 6888 2^3 * 3 * 7 * 41 32 %e A341655 24 89 7920 2^4 * 3^2 * 5 * 11 60 %t A341655 Table[DivisorSigma[0,Prime[n]^2-1],{n,66}] (* _Stefano Spezia_, Feb 25 2021 *) %o A341655 (PARI) a(n) = numdiv(prime(n)^2-1); \\ _Michel Marcus_, Feb 25 2021 %Y A341655 Cf. A000005, A000040, A084920, A309906. %K A341655 nonn %O A341655 1,1 %A A341655 _Jon E. Schoenfield_, Feb 25 2021