A143038 - OEIS

A143038

Triangle read by rows, A000012 * A134309 * A000012, where A134309 = an infinite lower triangular matrix with (1, 1, 2, 4, 8, 16, ...) in the main diagonal and the rest zeros.

1, 1, 2, 2, 3, 4, 4, 6, 7, 8, 8, 12, 14, 15, 16, 16, 24, 28, 30, 31, 32, 32, 48, 56, 60, 62, 63, 64, 64, 96, 112, 120, 124, 126, 127, 128, 128, 192, 224, 240, 248, 252, 254, 255, 256, 256, 384, 448, 480, 496, 504, 508, 510, 511, 512

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OFFSET

0,3

COMMENTS

Row sums = A002064, the Cullen numbers (1, 3, 9, 25, 65, 161, 385, ...).

LINKS

Table of n, a(n) for n=0..54.

FORMULA

a(n) = 2^i - 2^(i-1-j)*[j<i], where i = A003056(n), j = A002262(n). - Yuchun Ji, May 15 2020

EXAMPLE

First few rows of the triangle:

1, 2;