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 A173586 #3 Jul 12 2012 00:39:51 %S A173586 2,46,1502,96222,12316638,3153031134,1614350348254,1653094690025438, %T A173586 1692768964130074590,1733395419356639752158,1774996909423485572837342, %U A173586 3635193670499109531489365982 %N A173586 Decimal values a(n) of the binary numbers b(n) obtained by starting from first prime number (2), sequentially concatenating the binary representation of all prime numbers till n-th prime, and after that, sequentially concatenating the binary representation of all prime numbers, from (n-1)th till the first prime. %F A173586 a(n) = binary_to_decimal(concatenate(10, 11, 101, ..., binary((n-2)th prime), binary((n-1)th prime), binary(n-th prime), binary((n-1)th prime), binary((n-2)th prime), ..., 101, 11, 10)) %e A173586 a(1)=binary_to_decimal(10)=2, a(2)=binary_to_decimal(101110)=46, a(3)=binary_to_decimal(10111011110)=1502, a(4)=binary_to_decimal(10111011111011110)=96222 etc. %Y A173586 Cf. A066622. This sequence uses the term generation rule of A066622 (Concatenation of prime numbers in increasing order up to the n-th and then in decreasing order.), albeit with the binary base instead of the decimal base. %K A173586 base,nonn %O A173586 1,1 %A A173586 _Umut Uludag_, Feb 22 2010