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 A212170 #11 Jul 08 2023 16:12:11 %S A212170 1,2,48,207360,5643509760000,74508333765820416000000000, %T A212170 68238227014337640914957453230080000000000000000, %U A212170 958098594568198616022876832154309463351366075411333120000000000000000000000000 %N A212170 a(n) = first counting number with n distinct positive square exponents in its prime factorization. %C A212170 Next term has 122 digits. %C A212170 A166469(a(n))=(n+1)! Cf. A000142. %H A212170 Dario Alpern, <a href="https://www.alpertron.com.ar/ecm.htm">Factorization using the Elliptic Curve Method</a> %e A212170 a(2) = 48 = 2^4*3^1 has 2 distinct positive square exponents in its prime factorization (4 and 1 are both perfect squares). 48 is the smallest number with this property. %e A212170 Also, 48 has 3! = 6 divisors that are not divisible by any pair of consecutive primes: 1, 2, 3, 4, 8 and 16. Cf. A166469. %Y A212170 Cf. A000290. %Y A212170 Subsequence of A025487. Also see A002110, A006939, A066120, A166475, A167448. %K A212170 nonn %O A212170 1,2 %A A212170 _Matthew Vandermast_, May 24 2012