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 A156736 #7 Jun 02 2025 01:22:52 %S A156736 1,2,14,-1582,-7497258,303297921775458, %T A156736 -2646995089135122277190614296178, %U A156736 82888930564911423983289917045230098319343306166666586941750246 %N A156736 Signed greedy Egyptian fraction for Pi/2. %C A156736 The second and fourth convergents of Pi (22/7 and 355/113) appear when truncating the series to three and four terms. %H A156736 Wikipedia, <a href="http://en.wikipedia.org/wiki/Greedy_algorithm_for_Egyptian_fractions">Greedy algorithm for Egyptian fractions</a> %F A156736 Sum(n>=0,1/a(n))=Pi/2. %F A156736 a(n) = 2*A001467(n+1). - R. J. Mathar, Apr 02 2011 %e A156736 1+1/2+1/14=11/7=(1/2)(22/7) %e A156736 1+1/2+1/14-1/1582=355/226=(1/2)(355/113) %o A156736 (PARI) x=Pi/2; for (k=0,7, d=round(1/x); x=x-1/d; print1(d,", ")) %Y A156736 Cf. A001466, A156269, A156618. %Y A156736 Cf. A156750. [From _Jaume Oliver Lafont_, Mar 03 2009] %K A156736 sign %O A156736 0,2 %A A156736 _Jaume Oliver Lafont_, Feb 14 2009