cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A319063 A(n, k) is the k-th number b > 1 such that b^(prime(n+i)-1) == 1 (mod prime(n+i)^2) for each i = 0..5, with k running over the positive integers; square array, read by antidiagonals, downwards.

Original entry on oeis.org

132857, 171793, 2006776, 261593, 3091832, 296449, 618301, 3420818, 9654224, 17134811, 700993, 3524932, 11002557, 23250274, 36763941, 997757, 4108582, 16616568, 26073470, 195603158, 34998229, 1211201, 4349699, 20512643, 26646377, 307849316, 71724464
Offset: 1

Views

Author

Felix Fröhlich, Sep 09 2018

Keywords

Examples

			The array starts as follows:
    132857,    171793,    261593,    618301,    700993,    997757,   1211201
   2006776,   3091832,   3420818,   3524932,   4108582,   4349699,   4416499
    296449,   9654224,  11002557,  16616568,  20512643,  20950343,  21184318
  17134811,  23250274,  26073470,  26646377,  44247410,  49287925,  49975689
  36763941, 195603158, 307849316, 364769263, 366974980, 395009864, 428594624
  34998229,  71724464, 124024853, 279238292, 709701384, 710808570
		

Crossrefs

Cf. analog for i = 0..t: A319059 (t=1), A319060 (t=2), A319061 (t=3), A319062 (t=4), A319064 (t=6), A319065 (t=7).

Programs

  • Mathematica
    rows = 6; t = 5;
    T = Table[lst = {}; b = 2;
       While[Length[lst] < rows,
         p = Prime[n + Range[0, t]];
        If[AllTrue[PowerMod[b, (p - 1), p^2], # == 1 &],
         AppendTo[lst, b]]; b++];
       lst, {n, rows}];
    T // TableForm (* Print the A(n,k) table *)
    Flatten[Table[T[[j, i - j + 1]], {i, 1, rows}, {j, 1, i}]] (* Robert Price, Oct 01 2019 *)
  • PARI
    printrow(n, terms) = my(c=0); for(b=2, oo, my(j=0); for(i=0, 5, my(p=prime(n+i)); if(Mod(b, p^2)^(p-1)==1, j++)); if(j==6, print1(b, ", "); c++); if(c==terms, break))
    array(rows, cols) = for(x=1, rows, printrow(x, cols); print(""))
    array(8, 8) \\ print initial 8 rows and 8 columns of array