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A139593 A139276(n) followed by A139272(n+1). 9
0, 3, 11, 22, 38, 57, 81, 108, 140, 175, 215, 258, 306, 357, 413, 472, 536, 603, 675, 750, 830, 913, 1001, 1092, 1188, 1287, 1391, 1498, 1610, 1725, 1845, 1968, 2096, 2227, 2363, 2502, 2646, 2793, 2945, 3100, 3260, 3423, 3591, 3762 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Sequence found by reading the line from 0, in the direction 0, 3,... and the same line from 0, in the direction 0, 11,..., in the square spiral whose vertices are the triangular numbers A000217.

Contribution from Markus J. Q. Roberts (Markus(AT)reality.com), Jul 12 2009: (Start)

A139593 appears (both numerically and via back of an envelope algebra, but not a publishable proof) to be the cumulative sum of A047470

(End)

LINKS

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

FORMULA

Array read by rows: row n gives 8*n^2 + 3n, 8*(n+1)^2 - 5(n+1).

EXAMPLE

Array begins:

0, 3

11, 22

38, 57

81, 108

CROSSREFS

Cf. A000217, A046092, A139272, A139276, A077221, A139591, A139592, A139594, A139595, A139596, A139597, A139598.

Cf. A047470 [From Markus J. Q. Roberts (Markus(AT)reality.com), Jul 12 2009]

Sequence in context: A184053 A158653 A129215 * A121471 A178946 A087078

Adjacent sequences:  A139590 A139591 A139592 * A139594 A139595 A139596

KEYWORD

easy,nonn

AUTHOR

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

EXTENSIONS

Edited by Omar E. Pol (info(AT)polprimos.com), Jul 13 2009

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Last modified February 14 09:18 EST 2012. Contains 205614 sequences.