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A319064 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..6, with k running over the positive integers; square array, read by antidiagonals, downwards. 6
4486949, 4651993, 20950343, 4941649, 21184318, 23250274, 5571593, 33538051, 163075007, 741652533, 11903257, 78868324, 189850207, 882345432, 710808570, 19397501, 86892632, 230695118, 1528112512, 5126829291, 2380570527, 19841257, 111899224, 421883318, 1701241810 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..25.

EXAMPLE

The array starts as follows:

    4486949,    4651993,    4941649,    5571593,   11903257,   19397501,   19841257

   20950343,   21184318,   33538051,   78868324,   86892632,  111899224,  126664001

   23250274,  163075007,  189850207,  230695118,  421883318,  422771099,  497941351

  741652533,  882345432, 1528112512, 1701241810, 1986592318, 2005090271, 2596285385

  710808570, 5126829291

  2380570527

MATHEMATICA

rows = 6; t = 6; T = Table[lst = {}; b = 2;

   While[Length[lst] < rows - n + 1,

     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 03 2019 *)

PROG

(PARI) printrow(n, terms) = my(c=0); for(b=2, oo, my(j=0); for(i=0, 6, my(p=prime(n+i)); if(Mod(b, p^2)^(p-1)==1, j++)); if(j==7, print1(b, ", "); c++); if(c==terms, break))

array(rows, cols) = for(x=1, rows, printrow(x, cols); print(""))

array(5, 7) \\ print initial 5 rows and 7 columns of array

CROSSREFS

Cf. A244249, A256236.

Cf. analog for i = 0..t: A319059 (t=1), A319060 (t=2), A319061 (t=3), A319062 (t=4), A319063 (t=5), A319065 (t=7).

Sequence in context: A244575 A105649 A015337 * A183679 A234793 A227040

Adjacent sequences:  A319061 A319062 A319063 * A319065 A319066 A319067

KEYWORD

nonn,tabl

AUTHOR

Felix Fröhlich, Sep 11 2018

STATUS

approved

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Last modified April 5 13:26 EDT 2020. Contains 333241 sequences. (Running on oeis4.)