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A139596 A033587(n) followed by even hexagonal number A014635(n+1). 8
0, 6, 14, 28, 44, 66, 90, 120, 152, 190, 230, 276, 324, 378, 434, 496, 560, 630, 702, 780, 860, 946, 1034, 1128, 1224, 1326, 1430, 1540, 1652, 1770, 1890, 2016, 2144, 2278, 2414, 2556, 2700, 2850, 3002, 3160, 3320, 3486, 3654, 3828 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Sequence found by reading the line from 0, in the direction 0, 6,... and the same line from 0, in the direction 0, 14,..., in the square spiral whose vertices are the triangular numbers A000217.

LINKS

O. E. Pol, Determinacion geometrica de los numeros primos y perfectos.

FORMULA

Array read by rows: row n gives 8*n^2 + 6n, 8*(n+1)^2 - 2(n+1).

O.g.f.: -2x(x+3)/((x-1)^3*(1+x)). - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 06 2008

EXAMPLE

Array begins:

0, 6

14, 28

44, 66

90, 120

CROSSREFS

Cf. A000217, A014635, A033587, A046092, A077221, A139591, A139592, A139593, A139595, A139597, A139598.

Sequence in context: A071776 A063590 A128806 * A192035 A183023 A143702

Adjacent sequences:  A139593 A139594 A139595 * A139597 A139598 A139599

KEYWORD

easy,nonn

AUTHOR

Omar E. Pol (info(AT)polprimos.com), May 03 2008

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Last modified February 16 15:27 EST 2012. Contains 205930 sequences.