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 A143709 #4 Mar 30 2012 18:52:27 %S A143709 4,9,15,11,9,123,1594325,348,33,10,363,132,2071,11,27,2200,11,844, %T A143709 4656612873077392578127,136,131077,51,46,524291,172, %U A143709 45474735088646411895751953127,2230,15,14,8388655,19,51,28,291 %N A143709 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes (1^2+3, 2^2+5, 2^3+7, 2^3+3, 2^2+5, 11^2+2, 3^13+2, 7^3+5,..). %e A143709 a(8)=7^3+5=343+5=348. %e A143709 a(9)=2^4+17=16+17=43. %e A143709 a(10)=2^3+2=8+2=10. %e A143709 a(11)=19^2+2=361+2=363. %e A143709 a(12)=5^3+7=125+7=132. %e A143709 a(13)=2^11+23=2048+23=2071, %e A143709 etc. %Y A143709 Cf. A141287, A141261, A136735. %K A143709 nonn %O A143709 1,1 %A A143709 _Juri-Stepan Gerasimov_, Nov 13 2008 %E A143709 Corrected (15 replaced by 9, 43 by 33) and extended by _R. J. Mathar_, Apr 18 2010