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 A053520 #16 Jul 02 2025 16:01:59
%S A053520 2,8,38,74,1522,11986,11838,1054766,11506538,45706526,1772006854,
%T A053520 24681524038,11169012898,5874202721042,99515904921182,66139171377658,
%U A053520 3075946152109262,51924337160029042,4714400135799462226
%N A053520 Denominators of successive convergents to continued fraction 1/(2+2/(3+3/(4+4/(5+5/(6+6/(7+7/(8+8/9+...))))))).
%H A053520 M. A. Stern, <a href="http://gdz.sub.uni-goettingen.de/dms/load/img/?PID=GDZPPN002138999">Theorie der Kettenbrüche und ihre Anwendung</a>, Crelle, 1832, pp. 1-22.
%e A053520 Convergents are 1/2, 3/8, 15/38, 29/74, 597/1522, 4701/11986, ...
%p A053520 for j from 1 to 50 do printf(`%d,`,denom(cfrac([0,seq([i,i+1],i=1..j)]))); od:
%t A053520 a[n_] := ContinuedFractionK[k, k+1, {k, n+1}] // Denominator; Table[a[n], {n, 0, 18}] (* _Jean-François Alcover_, Mar 21 2016 *)
%Y A053520 Cf. A053518, A053519, A053556, A053557.
%K A053520 nonn,frac,nice,easy
%O A053520 0,1
%A A053520 _N. J. A. Sloane_, Jan 15 2000
%E A053520 More terms from _James Sellers_, Feb 02 2000