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 A077056 #15 Feb 02 2025 16:30:40
%S A077056 0,1,4,22,140,992,7584,61420,520320,4570292,41354416,383609434,
%T A077056 3634231140,35059333218,343580813492,3413862553800,34336784362232,
%U A077056 349131316634164,3584622273967324,37128374058146138,387630493693010928,4076329834240413392,43150916852592230992
%N A077056 Total number of "humps" in all A005316(2n) open meanders with 2n crossings.
%C A077056 A "hump" is a local maxima of the upper envelope of the part of the meander that extends above the East-West road.
%C A077056 A "hump" can also be described as an exterior top arch. - _Andrew Howroyd_, Feb 01 2025
%F A077056 a(n) = Sum_{k=1..n} k*A380369(n,k). - _Andrew Howroyd_, Feb 01 2025
%e A077056 The three open meanders with 4 crossings have respectively 2, 1 and 1 humps, so a(2) = 4.
%Y A077056 Cf. A005316 (open meanders), A077054, A380369.
%K A077056 nonn
%O A077056 0,3
%A A077056 _N. J. A. Sloane_ and _Jon Wild_, Nov 29 2002
%E A077056 a(9)-a(20) from _Andrew Howroyd_, Nov 22 2015
%E A077056 a(21)-a(22) from _Andrew Howroyd_, Feb 01 2025
%E A077056 a(0) corrected by _Andrew Howroyd_, Feb 02 2025