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 A342284 #15 Apr 02 2021 10:41:38 %S A342284 1,0,2,6,24,110,550,2922,16242,93520,553980,3359384,20777588, %T A342284 130696662,834244830,5393850898,35272830054,233016356788, %U A342284 1553427829684,10441803227652,70715551631992,482201548554776,3308810614160224,22836540660981088,158458108961055864 %N A342284 Number of friendly 3-watermelons of length n. %D A342284 Essam, J.W. and Guttmann, A.J., 1995. Vicious walkers and directed polymer networks in general dimensions. Physical Review E, 52(6), pp. 5849ff. See (63). %D A342284 Iwan Jensen, Three friendly walkers, Journal of Physics A: Mathematical and Theoretical, Volume 50:2 (2017), #24003, 14 pages; https://doi.org/10.1088/1751-8121/50/2/024003. See F_3(x). %F A342284 G.f. = 1 - 2*x + G(x), where G(x) = 2*x+2*x^2+6*x^3+24*x^4+110*x^5+550*x^6+... is the g.f. for A342282. %Y A342284 Cf. A001181, A342282. %K A342284 nonn %O A342284 0,3 %A A342284 _N. J. A. Sloane_, Mar 19 2021