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 A099722 From a 2-dimensional walk involving primes. 0
 11, 17, 23, 41, 47, 67, 83, 103, 157, 257, 277, 3407, 3517, 3547 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Start with 7 in the center cell. Rules: Write prime(n-1) in a cell and, if Prime(n-1) == 1 mod 5, then move to upper cell, append prime(n) to the cell. if Prime(n-1) == 2 mod 5, then move to right cell, append prime(n) to the cell. if Prime(n-1) == 3 mod 5, then move to lower cell, append prime(n) to the cell. if Prime(n-1) == 4 mod 5, then move to left cell, append prime(n) to the cell. Sequence gives sequence of primes appearing in the cell to the right of center cell. There are no more terms below 10^10. But two-dimensional random walks are recurrent, so this sequence is heuristically infinite. - Charles R Greathouse IV, Oct 18 2011 No more terms up to 10^12. - Charles R Greathouse IV, May 04 2020 No more terms up to 10^13. The associated position after 9999999999971 is (-3312, -57946). - Charles R Greathouse IV, May 29 2020 LINKS EXAMPLE .................. 13 ...... 13 ......... 13 .............. 13 ................. 7 -> 7 : 11 -> 7 : 11 -> 7 : 11,17 -> 7 : 11,17 : 19 -> 7 : 11,17,23 : 19 -> ... PROG (PARI) upto(lim)=my(x=-1, y=0, p=7); forprime(q=11, lim, if(p%5>2, if(p%5==3, y--, x--), if(p%5==1, y++, x++)); if(!x&&!y, print1(q", ")); p=q) \\ Charles R Greathouse IV, Oct 18 2011 CROSSREFS Cf. A096447. Sequence in context: A141250 A316188 A096454 * A031505 A094524 A243817 Adjacent sequences:  A099719 A099720 A099721 * A099723 A099724 A099725 KEYWORD nonn,more AUTHOR Yasutoshi Kohmoto, Nov 06 2004 EXTENSIONS a(8)-a(14) from Sean A. Irvine, Oct 18 2011 STATUS approved

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Last modified July 28 15:51 EDT 2021. Contains 346335 sequences. (Running on oeis4.)