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 A051869 #57 Dec 14 2022 18:43:43
%S A051869 0,1,17,48,94,155,231,322,428,549,685,836,1002,1183,1379,1590,1816,
%T A051869 2057,2313,2584,2870,3171,3487,3818,4164,4525,4901,5292,5698,6119,
%U A051869 6555,7006,7472,7953,8449,8960,9486,10027,10583,11154,11740,12341
%N A051869 17-gonal (or heptadecagonal) numbers: a(n) = n*(15*n-13)/2.
%C A051869 Sequence found by reading the line from 0, in the direction 0, 17,... and the parallel line from 1, in the direction 1, 48,..., in the square spiral whose vertices are the generalized 17-gonal numbers. - _Omar E. Pol_, Jul 18 2012
%D A051869 Albert H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, p. 189.
%D A051869 E. Deza and M. M. Deza, Figurate numbers, World Scientific Publishing (2012), page 6.
%H A051869 Ivan Panchenko, <a href="/A051869/b051869.txt">Table of n, a(n) for n = 0..1000</a>
%H A051869 <a href="/index/Pol#polygonal_numbers">Index to sequences related to polygonal numbers</a>
%H A051869 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A051869 G.f.: x*(1+14*x)/(1-x)^3. - _Bruno Berselli_, Feb 04 2011
%F A051869 a(n) = a(n-1) + 15*n - 14 with n>0, a(0)=0. - _Vincenzo Librandi_, Aug 06 2010
%F A051869 a(n) = A226489(n) - n. - _Bruno Berselli_, Jun 11 2013
%F A051869 a(15*a(n) + 106*n + 1) = a(15*a(n) + 106*n) + a(15*n+1). - _Vladimir Shevelev_, Jan 24 2014
%F A051869 E.g.f.: x*(2 + 15*x)*exp(x)/2. - _G. C. Greubel_, Aug 30 2019
%F A051869 Product_{n>=2} (1 - 1/a(n)) = 15/17. - _Amiram Eldar_, Jan 22 2021
%p A051869 A051869 := proc(n) n*(15*n-13)/2 ; end proc: seq(A051869(n),n=0..30) ; # _R. J. Mathar_, Feb 05 2011
%t A051869 Table[n*(15*n - 13)/2, {n,0,40}] (* _Robert Price_, Oct 11 2018 *)
%t A051869 PolygonalNumber[17,Range[0,50]] (* _Harvey P. Dale_, Dec 14 2022 *)
%o A051869 (PARI) a(n)=n*(15*n-13)/2 \\ _Charles R Greathouse IV_, Jan 24 2014
%o A051869 (Magma) [n*(15*n-13)/2: n in [0..40]]; // _G. C. Greubel_, Aug 30 2019
%o A051869 (Sage) [n*(15*n-13)/2 for n in (0..40)] # _G. C. Greubel_, Aug 30 2019
%o A051869 (GAP) List([0..40], n-> n*(15*n-13)/2); # _G. C. Greubel_, Aug 30 2019
%Y A051869 Cf. A002378.
%K A051869 nonn,easy
%O A051869 0,3
%A A051869 _N. J. A. Sloane_, Dec 15 1999