A054555 - OEIS

%I #21 Feb 19 2022 13:06:02

%S 2,7,47,139,283,503,797,1151,1579,2089,2689,3361,4099,4967,5861,6883,

%T 8011,9199,10457,11903,13313,14887,16547,18269,20161,22091,24083,

%U 26297,28573,30941,33347,35899,38593,41299,44111,47149,50131,53327,56597

%N Prime number spiral (clockwise, East spoke).

%C 8-spoke wheel overlays prime number spiral; hub is 2 in shell 0; 8 spokes radiate from this hub; this is East, clockwise.

%H Ivan Panchenko, <a href="/A054555/b054555.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) = A000040(A054556(n+1)). - _R. J. Mathar_, Aug 29 2018

%e Begin a prime number spiral at shell 0 (prime 2), proceed clockwise, East.

%e From _Omar E. Pol_, Feb 19 2022: (Start)

%e The spiral with four terms in every spoke looks like this:

%e .

%e   227  101--103--107--109--113--127

%e    |     |                       |

%e   223   97   29---31---37---41  131

%e    |     |    |              |   |

%e   211   89   23    3----5   43  137

%e    |     |    |    |    |    |   |

%e   199   83   19    2    7   47  139

%e    |     |    |         |    |   |

%e   197   79   17---13---11   53  149

%e    |     |                   |   |

%e   193   73---71---67---61---59  151

%e    |                             |

%e   191--181--179--173--167--163--157

%e .

%e (End)

%t Table[ Prime[4n^2 - 9n + 6], {n, 1, 40} ]

%Y Cf. A054556, A054551, A054553, A054564, A054566, A054568, A054570, A053999.

%K easy,nonn

%O 0,1

%A _Enoch Haga_, and _G. L. Honaker, Jr._, Apr 10 2000

%E Edited by _Robert G. Wilson v_, Feb 25 2002