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 A147296 #35 Dec 23 2024 14:53:42
%S A147296 0,11,40,87,152,235,336,455,592,747,920,1111,1320,1547,1792,2055,2336,
%T A147296 2635,2952,3287,3640,4011,4400,4807,5232,5675,6136,6615,7112,7627,
%U A147296 8160,8711,9280,9867,10472,11095,11736,12395,13072,13767,14480,15211,15960
%N A147296 a(n) = n*(9*n+2).
%C A147296 For n >= 1, the continued fraction expansion of sqrt(4*a(n)) is [6n; {1, 1, 1, 3n-1, 1, 1, 1, 12n}]. - _Magus K. Chu_, Sep 17 2022
%H A147296 Reply to V. Librandi, <a href="https://web.archive.org/web/*/http://list.seqfan.eu/oldermail/seqfan/2009-March/001017.html">A147296 (SeqFan list)</a>. - _M. F. Hasler_, Mar 01 2009
%H A147296 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A147296 a(n) = n*(9*n + 2), as conjectured by V. Librandi. - _M. F. Hasler_, Mar 01 2009
%F A147296 G.f.: x*(11+7*x)/(1-x)^3. - Jaume Oliver Lafont, Aug 30 2009
%F A147296 a(n) = floor((3*n + 1/3)^2). - _Reinhard Zumkeller_, Apr 14 2010
%F A147296 From _Elmo R. Oliveira_, Dec 15 2024: (Start)
%F A147296 E.g.f.: exp(x)*x*(11 + 9*x).
%F A147296 a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n >= 3. (End)
%t A147296 Table[n(9n+2),{n,0,50}] (* or *) LinearRecurrence[{3,-3,1},{0,11,40},50] (* _Harvey P. Dale_, Dec 19 2014 *)
%o A147296 (PARI) A147296(n) = n*(9*n + 2) \\ _M. F. Hasler_, Mar 01 2009
%Y A147296 Equals first 9-fold decimation of A144454.
%Y A147296 Cf. A010701, A017173, A147296, A185019.
%K A147296 nonn,easy
%O A147296 0,2
%A A147296 _Paul Curtz_, Nov 05 2008
%E A147296 More terms from _M. F. Hasler_, Mar 01 2009