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 A121610 #4 Mar 30 2012 18:50:55 %S A121610 44,46,48,49,64,66,68,69,84,86,88,94,96,98,99,104,106,108,124,126,128, %T A121610 129,144,146,148,154,156,158,159,164,166,168,169,184,186,188,189,204, %U A121610 206,208,209,214,216,218,219,224,226,228,244,246,248,249,254,256,258 %N A121610 Composite numbers that can be written as concatenation of two composite numbers in decimal representation. %e A121610 A002808(328) = 408 = 40*10+8 = A002808(27)*10+A002808(3), %e A121610 therefore 408 is a term: a(99) = 408; %e A121610 A002808(331) = 412 = 4*100+12 = A002808(1)*100+A002808(6), %e A121610 therefore 412 is a term: a(100) = 412. %Y A121610 Cf. A121609, A105184, A121608. %K A121610 nonn,base %O A121610 1,1 %A A121610 _Reinhard Zumkeller_, Aug 10 2006