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 A050441 #53 May 04 2022 07:00:19 %S A050441 0,1,14,50,120,235,406,644,960,1365,1870,2486,3224,4095,5110,6280, %T A050441 7616,9129,10830,12730,14840,17171,19734,22540,25600,28925,32526, %U A050441 36414,40600,45095,49910,55056,60544,66385,72590,79170,86136,93499,101270 %N A050441 Partial sums of A051865. %C A050441 This sequence is related to A180223 by 2*a(n) = n*A180223(n) - Sum_{i=0..n-1} A180223(i). Also, 13-gonal (or tridecagonal) pyramidal numbers. - _Bruno Berselli_, Dec 14 2010 %D A050441 A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 189-196. %D A050441 E. Deza and M. M. Deza, Figurate numbers, World Scientific Publishing (2012), page 93. %H A050441 Bruno Berselli, <a href="/A050441/b050441.txt">Table of n, a(n) for n = 0..1000</a> %H A050441 Bruno Berselli, A description of the recursive method in Comments lines: website <a href="http://www.lanostra-matematica.org/2008/12/sequenze-numeriche-e-procedimenti.html">Matem@ticamente</a> (in Italian), 2008. %H A050441 <a href="/index/Ps#pyramidal_numbers">Index to sequences related to pyramidal numbers</a> %H A050441 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1). %F A050441 a(n) = n*(n+1)*(11*n-8)/6. %F A050441 G.f.: x*(1+10*x)/(1-x)^4. - _Bruno Berselli_, Aug 19 2010 %F A050441 a(n) = 4*a(n-1)-6*a(n-2)+4*a(n-3)-a(n-4). - _Bruno Berselli_, Aug 19 2010 %F A050441 a(n) = Sum_{i=0..n-1} (n-i)*(11*i+1), with a(0)=0. - _Bruno Berselli_, Feb 10 2014 %F A050441 E.g.f.: exp(x)*x*(6 + 36*x + 11*x^2)/6. - _Stefano Spezia_, May 04 2022 %e A050441 After 0, the sequence is provided by the row sums of the triangle (see above, fourth formula): %e A050441 1; %e A050441 2, 12; %e A050441 3, 24, 23; %e A050441 4, 36, 46, 34; %e A050441 5, 48, 69, 68, 45; ... - _Vincenzo Librandi_, Feb 12 2014 %p A050441 seq(n*(n+1)*(11*n-8)/6, n=0..40); # _G. C. Greubel_, Aug 30 2019 %t A050441 Accumulate[Table[n (11n-9)/2,{n,0,40}]] (* or *) LinearRecurrence[ {4,-6,4,-1},{0,1,14,50},40] (* _Harvey P. Dale_, Nov 14 2011 *) %t A050441 CoefficientList[Series[x (1 + 10 x)/(1 - x)^4, {x, 0, 40}], x] (* _Vincenzo Librandi_, Feb 12 2014 *) %o A050441 (Magma) I:=[0,1,14,50]; [n le 4 select I[n] else 4*Self(n-1)-6*Self(n-2)+4*Self(n-3)-Self(n-4) : n in [1..50]]; // _Vincenzo Librandi_, Feb 12 2014 %o A050441 (PARI) a(n)=n*(n+1)*(11*n-8)/6 \\ _Charles R Greathouse IV_, Oct 07 2015 %o A050441 (Sage) [n*(n+1)*(11*n-8)/6 for n in (0..40)] # _G. C. Greubel_, Aug 30 2019 %o A050441 (GAP) List([0..40], n-> n*(n+1)*(11*n-8)/6); # _G. C. Greubel_, Aug 30 2019 %Y A050441 Cf. A051865, A180223. %Y A050441 Similar sequences are listed in A237616. %K A050441 nonn,easy,nice %O A050441 0,3 %A A050441 _Barry E. Williams_, Dec 23 1999