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 A131098 #47 Mar 21 2025 18:29:41
%S A131098 1,3,7,11,15,19,23,27,31,35,39,43,47,51,55,59,63,67,71,75,79,83,87,91,
%T A131098 95,99,103,107,111,115,119,123,127,131,135,139,143,147,151,155,159,
%U A131098 163,167,171,175,179,183,187,191,195,199,203,207,211,215,219,223,227,231,235,239
%N A131098 Partial sums of A151798.
%C A131098 1 together with A004767. - _Omar E. Pol_, Feb 23 2014
%H A131098 Vincenzo Librandi, <a href="/A131098/b131098.txt">Table of n, a(n) for n = 1..1000</a>
%H A131098 David Applegate, <a href="/A139250/a139250.anim.html">The movie version</a>
%H A131098 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A131098 a(1) = 1, a(n) = 4*n - 5 for n >= 2. - _Jaroslav Krizek_, Aug 15 2009
%F A131098 G.f.: x*(x+2*x^2+1)/(x-1)^2. - _R. J. Mathar_, Dec 08 2010
%F A131098 E.g.f.: exp(x)*(4*x - 5) + 5 + 2*x. - _Stefano Spezia_, Mar 21 2025
%e A131098 g.f. = x + 3*x^2 + 7*x^3 + 11*x^4 + 15*x^5 + 19*x^6 + 23*x^7 + 27*x^8 + ...
%t A131098 CoefficientList[Series[(x + 2 x^2 + 1)/(x - 1)^2, {x, 0, 80}], x] (* _Vincenzo Librandi_, Feb 25 2014 *)
%t A131098 LinearRecurrence[{2,-1},{1,3,7},70] (* _Harvey P. Dale_, Jan 03 2023 *)
%o A131098 (Magma) I:=[1,3,7]; [n le 3 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..70]]; // _Vincenzo Librandi_, Feb 25 2014
%o A131098 (PARI) A131098(n)=abs(4*n-5) \\ _M. F. Hasler_, Apr 27 2018
%Y A131098 Cf. A151798, A004767.
%K A131098 nonn,easy
%O A131098 1,2
%A A131098 _Hans Isdahl_, Sep 24 2007
%E A131098 Edited by _N. J. A. Sloane_, Jun 29 2009