A200748
Smallest number requiring n terms to be expressed as a sum of factorials.
Original entry on oeis.org
0, 1, 3, 5, 11, 17, 23, 47, 71, 95, 119, 239, 359, 479, 599, 719, 1439, 2159, 2879, 3599, 4319, 5039, 10079, 15119, 20159, 25199, 30239, 35279, 40319, 80639, 120959, 161279, 201599, 241919, 282239, 322559, 362879, 725759, 1088639, 1451519, 1814399, 2177279
Offset: 0
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With[{b = MixedRadix[Reverse@ Range[2, 12]]}, Function[s, {0}~Join~Map[FirstPosition[s, #][[1]] &, Union@ FoldList[Max, s]]]@ Array[Total@ IntegerDigits[#, b] &, 10^5]] (* or *)
Prepend[-1 + Rest@ Flatten[Table[n!*k, {n, 9}, {k, n}]], 0] (* Michael De Vlieger, Sep 03 2017, after Jean-François Alcover at A051683 *)
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k=0;m=1;s=0;vector(45,n,s+=m!;if(k++==m,k=0;m++);s)
A130478
Triangle T(n,k) = n! / A130477(n,k).
Original entry on oeis.org
1, 2, 2, 6, 3, 2, 24, 8, 3, 2, 120, 30, 8, 3, 2, 720, 144, 30, 8, 3, 2, 5040, 840, 144, 30, 8, 3, 2, 40320, 5760, 840, 144, 30, 8, 3, 2, 362880, 45360, 5760, 840, 144, 30, 8, 3, 2, 3628800, 403200, 45360, 5760, 840, 144, 30, 8, 3, 2
Offset: 1
First few rows of the triangle:
1;
2, 2;
6, 3, 2;
24, 8, 3, 2;
120, 30, 8, 3, 2;
720, 144, 30, 8, 3, 2;
5040, 840, 144, 30, 8, 3, 2;
...
Row 4 = (24, 8, 3, 2), terms such that (24, 8, 3, 2) dot (1, 3, 8, 12) = (24, 24, 24, 24), where (1, 3, 8, 12) = row 4 of A130477 and (24, 24, 24, 24) = row 4 of A130493.
Row 5 = (120, 30, 8, 3, 2) = 5! + (4!+3!) + (3!+2!) + (2!+1!) + (1!+1).
Row 5 = 120 followed by the first reversed 4 terms of A001048; i.e., 120 followed by 30, 8, 3, 2.
A343041
a(0) = 0 and for any n > 0, a(n) = A343040(a(n-1), n).
Original entry on oeis.org
0, 1, 3, 3, 5, 5, 11, 11, 11, 11, 11, 11, 17, 17, 17, 17, 17, 17, 23, 23, 23, 23, 23, 23, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 71, 71, 71, 71, 71, 71, 71, 71, 71, 71, 71, 71, 71, 71, 71, 71, 71, 71, 71
Offset: 0
The first terms, in decimal and in factorial base, are:
n a(n) fact(n) fact(a(n))
-- ---- ------- ----------
0 0 0 0
1 1 1 1
2 3 10 11
3 3 11 11
4 5 20 21
5 5 21 21
6 11 100 121
7 11 101 121
8 11 110 121
9 11 111 121
10 11 120 121
11 11 121 121
12 17 200 221
13 17 201 221
14 17 210 221
Showing 1-3 of 3 results.
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