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 A371984 #10 May 11 2024 16:51:54 %S A371984 1,3,15,117,1227,16053,251955,4613997,96566667,2273672133,59482039395, %T A371984 1711735382877,53737315411707,1827584253650613,66936582030410835, %U A371984 2626714554845111757,109948916113808074347,4889877314768678051493 %N A371984 Binomial transform of A371460. %F A371984 a(0) = 1, a(n) = Sum_{j=1..n} (1-(-2)^j)*binomial(n,j)*a(n-j) for n > 0. %F A371984 a(0) = 1, a(n) = 2^n + Sum_{j=1..n} (3^j-2^j)*binomial(n,j)*a(n-j) for n > 0. %F A371984 E.g.f.: exp(2*x)/(1 + exp(2*x) - exp(3*x)). %t A371984 nn = 17; a[0] = 1; Do[Set[a[n], 2^n + Sum[(3^j - 2^j)*Binomial[n, j]*a[n - j], {j, n}]], {n, nn}]; Array[a, nn + 1, 0] (* _Michael De Vlieger_, Apr 19 2024 *) %o A371984 (SageMath) %o A371984 def a(n): %o A371984 if n==0: %o A371984 return 1 %o A371984 else: %o A371984 return sum([(1-(-2)^j)*binomial(n,j)*a(n-j) for j in [1,..,n]]) %o A371984 list(a(n) for n in [0,..,20]) %o A371984 (SageMath) %o A371984 f= e^(2*x)/(1 + e^(2*x) - e^(3*x)) %o A371984 print([(diff(f,x,i)).subs(x=0) for i in [0,..,20]]) %Y A371984 Cf. A371460. %K A371984 nonn %O A371984 0,2 %A A371984 _Prabha Sivaramannair_, Apr 15 2024