The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A204137 Triangle T(r+1,c) = |T(r,c) - T(r,c+1)| of positive integers such that T(r,c) is prime iff r=1 and no number occurs twice. 1
 2, 3, 1, 13, 10, 9, 47, 34, 24, 15, 197, 150, 116, 92, 77, 11, 186, 36, 80, 12, 65, 29, 18, 168, 132, 52, 40, 25, 443, 414, 396, 228, 96, 44, 4, 21, 397, 46, 368, 28, 200, 104, 60, 56, 35, 1321, 924, 878, 510, 482, 282, 178, 118, 62, 27, 4831, 3510, 2586 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS For each n>0, T(1,n) = A203985(n) is the smallest prime such that the constraints are satisfied for r+c <= n+1. It is conjectured that the first row of the table is a permutation of the primes and the whole table, i.e., this sequence, a permutation of the positive integers. LINKS Table of n, a(n) for n=1..58. Eric Angelini, An array of naturals, Jan 07 2012 Eric Angelini, An array of naturals [Cached copy, with permission] EXAMPLE The triangle starts r=1: 2 3 13 47 ... <- primes r=2: 1 10 34 ... r=3: 9 24 ... r=4: 15 ... which is the smallest solution as can be seen from the fact that the first column contains so far the smallest odd nonprimes. This does not remain true for subsequent rows; the triangle is determined by imposing minimality of the elements of the first row. See the link for more data. PROG (PARI) table_by_antidiagonals(a)={my(u=[]); for(i=1, #a, u=concat(u, a[i]); forstep(j=i-1, 1, -1, u=concat(u, a[j]=abs(a[j]-a[j+1])))); u} A204137=table_by_antidiagonals( A203985 ) \\ M. F. Hasler, Jan 11 2012 CROSSREFS Cf. A203985. Sequence in context: A176701 A107415 A079174 * A102583 A030780 A193683 Adjacent sequences: A204134 A204135 A204136 * A204138 A204139 A204140 KEYWORD nonn,tabl AUTHOR Eric Angelini, Jan 07 2012 EXTENSIONS Computed up to a(70*71/2) by Jean-Marc Falcoz, Jan 09 2012 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 30 04:46 EDT 2024. Contains 372958 sequences. (Running on oeis4.)