A220099 -id:A220099 - cp's OEIS frontend

A220100 Sum of the four nearest neighbors of n in a double spiral with positive integers and 1 at the center.

18, 27, 26, 42, 42, 34, 35, 42, 42, 74, 74, 58, 58, 66, 66, 106, 106, 82, 82, 90, 90, 98, 98, 106, 106, 154, 154, 122, 122, 130, 130, 138, 138, 146, 146, 202, 202, 162, 162, 170, 170, 178, 178, 186, 186, 194, 194, 202, 202, 266, 266, 218, 218, 226, 226, 234, 234, 242

Offset: 1

Alex Ratushnyak, Dec 04 2012

Double spiral begins:
.
  82---84---86---88---90---92---94---96---98
   |
  80   51---53---55---57---59---61---63---65
   |    |                                  |
  78   49   26---28---30---32---34---36   67
   |    |    |                        |    |
  76   47   24   11---13---15---17   38   69
   |    |    |    |              |    |    |
  74   45   22    9    2----4   19   40   71
   |    |    |    |    |    |    |    |    |
  72   43   20    7    1    6   21   42   73
   |    |    |    |    |    |    |    |    |
  70   41   18    5----3    8   23   44   75
   |    |    |              |    |    |    |
  68   39   16---14---12---10   25   46   77
   |    |                        |    |    |
  66   37---35---33---31---29---27   48   79
   |                                  |    |
  64---62---60---58---56---54---52---50   81
                                           |
  99---97---95---93---91---89---87---85---83

			The four nearest neighbors of 8 are 3, 6, 23, 10; their sum is a(8)=42.
The four nearest neighbors of 9 are 22, 11, 2, 7; their sum is a(9)=42.

Cf. A220098, A220099.

cp's OEIS Frontend

A220100 Sum of the four nearest neighbors of n in a double spiral with positive integers and 1 at the center.

Views

Author

Keywords

Comments

Examples

Crossrefs