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 A382514 #18 Apr 09 2025 23:40:05 %S A382514 1,1,7,43,255,1493,8695,50517,293163,1700335,9859019,57156631, %T A382514 331332423,1920621431,11132911939,64531189379,374047777319, %U A382514 2168115796941,12567146992975,72843402779669,422224417571347,2447350774345341,14185640454054279,82224565359415849 %N A382514 Expansion of 1/(1 - x/(1 - 4*x)^(3/2)). %H A382514 Vincenzo Librandi, <a href="/A382514/b382514.txt">Table of n, a(n) for n = 0..300</a> %F A382514 a(n) = Sum_{k=0..n} 4^(n-k) * binomial(n+k/2-1,n-k). %F A382514 D-finite with recurrence (-n+1)*a(n) +2*(8*n-13)*a(n-1) +5*(-19*n+43)*a(n-2) +2*(126*n-361)*a(n-3) +128*(-2*n+7)*a(n-4)=0. - _R. J. Mathar_, Mar 31 2025 %t A382514 Table[Sum[4^(n-k)*Binomial[n+k/2-1,n-k],{k,0,n}],{n,0,35}] (* _Vincenzo Librandi_, Apr 09 2025 *) %o A382514 (PARI) a(n) = sum(k=0, n, 4^(n-k)*binomial(n+k/2-1, n-k)); %o A382514 (Magma) R<x> := PowerSeriesRing(Rationals(), 40); f := 1/(1 - x/(1 - 4*x)^(3/2)); seq := [ Coefficient(f, n) : n in [0..30] ]; seq; // _Vincenzo Librandi_, Apr 09 2025 %Y A382514 Cf. A026671, A382515. %Y A382514 Cf. A002457. %K A382514 nonn,easy %O A382514 0,3 %A A382514 _Seiichi Manyama_, Mar 30 2025