A077056 Total number of "humps" in all A005316(2n) open meanders with 2n crossings.

0, 1, 4, 22, 140, 992, 7584, 61420, 520320, 4570292, 41354416, 383609434, 3634231140, 35059333218, 343580813492, 3413862553800, 34336784362232, 349131316634164, 3584622273967324, 37128374058146138, 387630493693010928, 4076329834240413392, 43150916852592230992

Offset: 0

Author

N. J. A. Sloane and Jon Wild, Nov 29 2002

Keywords

• nonn

Comments

A "hump" is a local maxima of the upper envelope of the part of the meander that extends above the East-West road.

A "hump" can also be described as an exterior top arch. - Andrew Howroyd, Feb 01 2025

Examples

			The three open meanders with 4 crossings have respectively 2, 1 and 1 humps, so a(2) = 4.
		

Crossrefs

Cf. A005316 (open meanders), A077054, A380369.

Formula

a(n) = Sum_{k=1..n} k*A380369(n,k). - Andrew Howroyd, Feb 01 2025

Extensions

a(9)-a(20) from Andrew Howroyd, Nov 22 2015

a(21)-a(22) from Andrew Howroyd, Feb 01 2025

a(0) corrected by Andrew Howroyd, Feb 02 2025