

A277973


Sum of horizontal positions of the first peak in all bargraphs of semiperimeter n.


1



0, 0, 0, 1, 6, 25, 91, 311, 1029, 3346, 10778, 34544, 110444, 352785, 1126885, 3601617, 11521648, 36899528, 118322448, 379908707, 1221423149, 3932113059, 12675055399, 40909511880, 132200481507, 427718677728, 1385419058692, 4492446685542, 14582927712740, 47385785436719
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OFFSET

1,5


COMMENTS

Horizontal position is xcoordinate of the start of the leftmost horizontal step of the first peak.


LINKS

Table of n, a(n) for n=1..30.
A. Blecher, C. Brennan, and A. Knopfmacher, Peaks in bargraphs, Trans. Royal Soc. South Africa, 71, No. 1, 2016, 97103.


FORMULA

G.f.: (2*x^3*(x^2sqrt(x^4+2*x^24*x+1)+1)) / ((1x)*(x^2+sqrt(x^4+2*x^24*x+1)2*x+1)^2).


EXAMPLE

For n = 4, a(4) = 1, as only the bargraph with first column of height one and second column of height two has horizontal position 1, all other cases are zero.


CROSSREFS

Cf. A271941, A273720, A273345.
Sequence in context: A000392 A099948 A333017 * A143815 A209241 A092491
Adjacent sequences: A277970 A277971 A277972 * A277974 A277975 A277976


KEYWORD

nonn


AUTHOR

Arnold Knopfmacher, Nov 07 2016


STATUS

approved



