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 A375077 #22 Sep 01 2025 11:03:21
%S A375077 2,2480,8178,45153,3648841,7979090,101130029
%N A375077 Smallest k such that Product_{i=0..n} (k-i) divides C(2k,k).
%H A375077 Thomas Bloom, <a href="https://www.erdosproblems.com/396">Problem 396</a>, Erdős Problems.
%o A375077 (PARI) for(n=1,20,for(k=n+1,100000,if(binomial(2*k,k)%prod(i=0,n,k-i)==0,print(n," ",k);break)))
%o A375077 (Python)
%o A375077 from math import prod, comb
%o A375077 def A375077(n):
%o A375077 a, c, k = prod(n+1-i for i in range(n+1)), comb(n+1<<1,n+1), n+1
%o A375077 while c%a:
%o A375077 k += 1
%o A375077 a = a*k//(k-n-1)
%o A375077 c = c*((k<<1)-1<<1)//k
%o A375077 return k # _Chai Wah Wu_, Jul 30 2024
%Y A375077 Cf. A000984, A120626, A129489.
%K A375077 nonn,hard,more,changed
%O A375077 1,1
%A A375077 _Ralf Stephan_, Jul 29 2024
%E A375077 a(5) from _Chai Wah Wu_, Aug 01 2024
%E A375077 a(6)-a(7) from _Max Alekseyev_, Feb 25 2025