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 A290440 #7 Aug 28 2017 01:02:44 %S A290440 1,2,4,12,19,46,88,185,380,793,1589,3106,6078,12147,24534,49482,99792, %T A290440 201892,408478 %N A290440 a(n) = A289677(3*n+2). %C A290440 No formulas or recurrences are known for the important sequences A289670 and A289671. The essence of these two sequences is captured in the six entries A290436-A290441. Any numerical properties of these would be most welcome. %Y A290440 Cf. A284116, A284119, A284121, A289670-A289677, A290436-A290441. %K A290440 nonn,more %O A290440 0,2 %A A290440 _N. J. A. Sloane_, Aug 02 2017