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A214177 Sum of the 4 nearest neighbors of n in a spiral with positive integers. 6
20, 24, 32, 24, 44, 32, 56, 40, 44, 72, 52, 56, 88, 64, 68, 72, 108, 80, 84, 88, 128, 96, 100, 104, 108, 152, 116, 120, 124, 128, 176, 136, 140, 144, 148, 152, 204, 160, 164, 168, 172, 176, 232, 184, 188, 192, 196, 200, 204, 264, 212, 216, 220, 224, 228, 232, 296 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Nearby numbers on diagonals are not counted as neighbors for this sequence.

LINKS

Rémy Sigrist, Table of n, a(n) for n = 1..5202

Rémy Sigrist, PARI program for A214177

EXAMPLE

Spiral begins:

.

  49  26--27--28--29--30--31

   |   |                   |

  48  25  10--11--12--13  32

   |   |   |           |   |

  47  24   9   2---3  14  33

   |   |   |   |   |   |   |

  46  23   8   1   4  15  34

   |   |   |       |   |   |

  45  22   7---6---5  16  35

   |   |               |   |

  44  21--20--19--18--17  36

   |                       |

  43--42--41--40--39--38--37

.

The four nearest neighbors of 2 are 1, 3, 9, 11. Their sum is a(2) = 24.

PROG

(PARI) See Links section.

CROSSREFS

Cf. A137928, A137930, A137931, A002061, A114254.

Cf. A214176 (sum of the 8 nearest neighbors).

Sequence in context: A109131 A171696 A060461 * A044996 A263016 A107302

Adjacent sequences:  A214174 A214175 A214176 * A214178 A214179 A214180

KEYWORD

nonn,easy

AUTHOR

Alex Ratushnyak, Jul 06 2012

STATUS

approved

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Last modified July 24 11:17 EDT 2021. Contains 346273 sequences. (Running on oeis4.)