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 A308094 Arrange distinct numbers in a single square spiral so that the absolute difference between each number and its eight neighbors is unique. 0
 1, 2, 4, 8, 13, 21, 10, 31, 17, 34, 52, 26, 45, 68, 41, 66, 97, 131, 57, 96, 50, 139, 69, 114, 165, 83, 219, 107, 168, 102, 158, 221, 136, 198, 265, 166, 3, 237, 309, 386, 183, 261, 140, 349, 240, 319, 411, 270, 363, 179, 461, 322, 426, 279, 381, 488, 6, 364 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Start with 1; always choose smallest number which has not yet appeared. LINKS EXAMPLE The spiral begins: .    673--476--896--714--200--610--848--660--181--831--180      |                                                 |    877  125--280--513--393----9--336--481--364----6  658      |    |                                       |    |   1085  429    3--166--265--198--136--221--158  488  187      |    |    |                             |    |    |    770  554  237   97---66---41---68---45  102  381  647      |    |    |    |                   |    |    |    |    232    7  309  131   13----8----4   26  168  279   18      |    |    |    |    |         |    |    |    |    |    743  523  386   57   21    1----2   52  107  426  584      |    |    |    |    |              |    |    |    |    964   14  183   96   10---31---17---34  219  322   12      |    |    |    |                        |    |    |   1182  405  261   50--139---69--114--165---83  461  842      |    |    |                                  |    |    765  539  140--349--240--319--411--270--363--179  680      |    |                                            |    233    5--685--499---11--572---16--565---19--514---15 CROSSREFS Cf. A175498, A257339. Sequence in context: A130840 A115266 A164508 * A292774 A026039 A004978 Adjacent sequences:  A308091 A308092 A308093 * A308095 A308096 A308097 KEYWORD nonn AUTHOR Luca Petrone, May 12 2019 STATUS approved

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Last modified September 16 23:53 EDT 2021. Contains 347477 sequences. (Running on oeis4.)