A269298 - OEIS

A269298

Central nonzero values of A231599.

1, 2, 2, 4, 6, 8, 16, 28, 50, 100, 196, 388, 786, 1600, 3280, 6780, 14060, 29280, 61232, 128414, 270084, 569514, 1203564, 2548770, 5407754, 11493312, 24465960, 52157508, 111342192, 237985596, 509275390, 1091017632, 2339687834, 5022312654, 10790564790

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OFFSET

0,2

COMMENTS

Rows of A231599 whose row number is divisible by four have positive central values. a(n) is the central value of row 4n. They are also the maximal value of that row, so a(n) = A086376(4n).

a(1) = a(2) = 2. Apart from that the sequence is strictly increasing.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..250 (first 101 trms from Tilman Piesk)

Dorin Andrica and Ovidiu Bagdasar, On some results concerning the polygonal polynomials, Carpathian Journal of Mathematics (2019) Vol. 35, No. 1, 1-11.

Tilman Piesk, A231599 as a centered table (first 11 values visible)

FORMULA

a(n) = A231599( 4n, A000217(4n)/2 ) = A086376(4n).

EXAMPLE

For n = 5, A231599( 4n, A000217(4n)/2 ) = A231599(20, 105) = 8, so a(5)=8.

For n = 5, A086376(4n) = A086376(20) = 8, so a(5)=8.

CROSSREFS

Cf. A231599, A086376.

Sequence in context: A239851 A153958 A216214 * A153964 A001010 A357952

Adjacent sequences: A269295 A269296 A269297 * A269299 A269300 A269301

KEYWORD

nonn

AUTHOR

Tilman Piesk, Feb 21 2016

STATUS

approved