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 A053155 #26 Jan 29 2023 19:31:53
%S A053155 0,1,7,50,397,3366,29197,253030,2170357,18385046,153927037,1275981510,
%T A053155 10492253317,85727548726,696964520077,5644579061990,45579645264277,
%U A053155 367223771048406,2953549834748317,23724145930814470,190373553357763237
%N A053155 Number of 3-element intersecting families (with not necessarily distinct sets) of an n-element set.
%H A053155 G. C. Greubel, <a href="/A053155/b053155.txt">Table of n, a(n) for n = 0..1000</a>
%H A053155 V. Jovovic, G. Kilibarda, <a href="http://dx.doi.org/10.4213/dm398">On the number of Boolean functions in the Post classes F^{mu}_8</a>, (in Russian), Diskretnaya Matematika, 11 (1999), no. 4, 127-138.
%H A053155 V. Jovovic, G. Kilibarda, <a href="http://dx.doi.org/10.1515/dma.1999.9.6.593">On the number of Boolean functions in the Post classes F^{mu}_8</a>, (English translation), Discrete Mathematics and Applications, 9, (1999), no. 6.
%H A053155 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (29,-343,2135,-7504,14756,-14832,5760).
%F A053155 a(n) = (8^n - 3*6^n + 3*5^n + 2*4^n - 3*3^n + 2*2^n - 2)/6.
%F A053155 G.f.: x*(1224*x^5-1562*x^4+787*x^3-190*x^2+22*x-1)/((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)*(6*x-1)*(8*x-1)). - _Colin Barker_, Jul 29 2012
%F A053155 a(n) = 29*a(n-1) - 343*a(n-2) + 2135*a(n-3) - 7504*a(n-4) + 14756*a(n-5) - 14832*a(n-6) + 5760*a(n-7) for n > 6. - _Wesley Ivan Hurt_, Oct 06 2017
%p A053155 A053155:=n->(8^n - 3*6^n + 3*5^n + 2*4^n - 3*3^n + 2*2^n - 2)/6: seq(A053155(n), n=0..30); # _Wesley Ivan Hurt_, Oct 06 2017
%t A053155 Table[(8^n - 3*6^n + 3*5^n + 2*4^n - 3*3^n + 2*2^n - 2)/6, {n, 0, 50}] (* _G. C. Greubel_, Oct 06 2017 *)
%t A053155 LinearRecurrence[{29, -343, 2135, -7504, 14756, -14832, 5760}, {0, 1, 7, 50, 397, 3366, 29197}, 30] (* _Vincenzo Librandi_, Oct 07 2017 *)
%o A053155 (PARI) for(n=0,50, print1((8^n - 3*6^n + 3*5^n + 2*4^n - 3*3^n + 2*2^n - 2)/6, ", ")) \\ _G. C. Greubel_, Oct 06 2017
%o A053155 (Magma) [(8^n - 3*6^n + 3*5^n + 2*4^n - 3*3^n + 2*2^n - 2)/6: n in [0..50]]; // _G. C. Greubel_, Oct 06 2017
%Y A053155 Cf. A051180.
%K A053155 easy,nonn
%O A053155 0,3
%A A053155 _Vladeta Jovovic_, Goran Kilibarda, Feb 28 2000