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 A319061 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..3, with k running over the positive integers; square array, read by antidiagonals, downwards. 7
 557, 901, 1207, 1549, 4607, 1451, 2449, 5176, 2774, 13543, 4049, 10124, 8201, 42269, 24675, 5293, 19601, 13543, 91110, 45124, 39016, 5849, 20924, 24482, 91678, 95236, 302947, 217682, 6193, 22049, 30949, 101399, 188872, 387587, 928423, 165407, 7057, 26018 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE The array starts as follows:      557,    901,    1549,    2449,    4049,    5293,    5849,    6193     1207,   4607,    5176,   10124,   19601,   20924,   22049,   26018     1451,   2774,    8201,   13543,   24482,   30949,   31457,   40199    13543,  42269,   91110,   91678,  101399,  132576,  142148,  210258    24675,  45124,   95236,  188872,  236915,  273971,  296449,  298117    39016, 302947,  387587,  609436,  637111,  962525, 1015033, 1074751   217682, 928423, 1546225, 1666084, 1756986, 2105290, 2673538, 2733520   165407, 215029, 1008933, 1370816, 1487743, 1493395, 1624207, 2998943 MATHEMATICA rows = 8; t = 3; 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, Sep 30 2019 *) PROG (PARI) printrow(n, terms) = my(c=0); for(b=2, oo, my(j=0); for(i=0, 3, my(p=prime(n+i)); if(Mod(b, p^2)^(p-1)==1, j++)); if(j==4, print1(b, ", "); c++); if(c==terms, break)) array(rows, cols) = for(x=1, rows, printrow(x, cols); print("")) array(8, 10) \\ print initial 8 rows and 10 columns of array CROSSREFS Cf. A244249, A256236. Cf. analog for i = 0..t: A319059 (t=1), A319060 (t=2), A319062 (t=4), A319063 (t=5), A319064 (t=6), A319065 (t=7). Sequence in context: A233355 A177331 A289564 * A339533 A260066 A105979 Adjacent sequences:  A319058 A319059 A319060 * A319062 A319063 A319064 KEYWORD nonn,tabl AUTHOR Felix FrÃ¶hlich, Sep 09 2018 STATUS approved

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Last modified May 6 09:45 EDT 2021. Contains 343580 sequences. (Running on oeis4.)