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 A291925 A(n,k) is the n-th Rhonda number to base A002808(k), the k-th composite number; square array A(n,k), n>=1, k>=1, read by antidiagonals. 18
 10206, 855, 11935, 1836, 1029, 12150, 15540, 6318, 3813, 16031, 1568, 21054, 6622, 5577, 45030, 560, 2835, 25331, 10530, 7040, 94185, 11475, 800, 4752, 44360, 14500, 7304, 113022, 2392, 18655, 3993, 5265, 44660, 14739, 15104, 114415, 1000, 2472, 20565, 4425, 5439, 44733, 17655, 19136, 191149 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Integer m is Rhonda number to base b if the product of its base-b digits divided by b is equal to the integer log of m, A001414(m). This can only happen if b is a composite number, b in {A002808}. LINKS Alois P. Heinz, Antidiagonals n = 1..141, flattened Eric Weisstein's World of Mathematics, Rhonda Number EXAMPLE A(1,2) = 855 is the first and smallest term of column k=2. The second composite number is A002808(2) = 6. 855 = (((3*6)+5)*6+4)*6+3 = 3543_6 = 3*3*5*19. And (3*5*4*3)/6 = A001414(855) = 3+3+5+19 = 30. Square array A(n,k) begins: : 10206, 855, 1836, 15540, 1568, 560, 11475, ... : 11935, 1029, 6318, 21054, 2835, 800, 18655, ... : 12150, 3813, 6622, 25331, 4752, 3993, 20565, ... : 16031, 5577, 10530, 44360, 5265, 4425, 29631, ... : 45030, 7040, 14500, 44660, 5439, 4602, 31725, ... : 94185, 7304, 14739, 44733, 5664, 4888, 45387, ... : 113022, 15104, 17655, 47652, 5824, 7315, 58404, ... CROSSREFS Columns k=1-11,19,42 give: A100968, A100969, A100970, A100973, A099542, A100971, A100972, A100974, A100975, A255735, A255732, A255736, A255731. Row n=1 gives A255872. Main diagonal gives A255880. Cf. A001414, A002808, A100987, A100988, A217986. Sequence in context: A243819 A258890 A255872 * A255880 A100968 A203056 Adjacent sequences: A291922 A291923 A291924 * A291926 A291927 A291928 KEYWORD nonn,tabl,look AUTHOR Alois P. Heinz, Sep 05 2017 STATUS approved

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Last modified February 24 14:26 EST 2024. Contains 370305 sequences. (Running on oeis4.)