Original entry on oeis.org
4, 39, 324, 2799, 24999, 228570, 2124999, 19999999, 189999999, 1818181817, 17499999999, 169230769229, 1642857142856, 15999999999999, 156249999999999, 1529411764705881, 14999999999999999, 147368421052631577, 1449999999999999999, 14285714285714285713
Offset: 1
The triangle starts in row n=1 as
4 9 # -1, -1+5, -1+2*5
39 69 99 # 9,9+30,9+2*30
324 549 774 999 # 99, 99+225, 99+2*225, 99+3*225
2799 4599 6399 8199 9999 # 999, 999+1800, 999+2*1800,..
...
The sequence contains the first column.
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[10^(n-1) -1 +Floor(9*10^(n-1)/(n+1)): n in [1..20]]; // G. C. Greubel, Apr 02 2019
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A093851 := proc(n) 10^(n-1)-1+floor(9*10^(n-1)/(n+1)) ; end proc: seq(A093851(n),n=1..20) ; # R. J. Mathar, Oct 14 2010
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Table[10^(n-1) -1 +Floor[9*10^(n-1)/(n+1)], {n, 1, 20}] (* G. C. Greubel, Apr 02 2019 *)
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{a(n) = 10^(n-1) -1 +floor(9*10^(n-1)/(n+1))}; \\ G. C. Greubel, Apr 02 2019
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[10^(n-1) -1 +floor(9*10^(n-1)/(n+1)) for n in (1..20)] # G. C. Greubel, Apr 02 2019
A181354
Number of n-digit perfect cubes.
Original entry on oeis.org
2, 2, 5, 12, 25, 53, 116, 249, 535, 1155, 2487, 5358, 11545, 24871, 53584, 115444, 248715, 535841, 1154435, 2487154, 5358411, 11544347, 24871542, 53584111, 115443470, 248715414, 535841116, 1154434691, 2487154143, 5358411166
Offset: 1
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a:=n->ceil(10^(n/3))-ceil(10^((n-1)/3));
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With[{c = Range[4650000]^3}, Length[#]&/@Table[Select[c, IntegerLength[#] == n &], {n, 20}]] (* Harvey P. Dale, Feb 01 2011 *)
Differences[Ceiling[10^(Range[0, 30]/3)]]
A186654
Total number of n-digit numbers requiring 4 positive biquadrates in their representation as sum of biquadrates.
Original entry on oeis.org
1, 6, 41, 298, 2720, 24688, 232970, 2255588, 22228377, 220476980, 2197066826
Offset: 1
A186656
Total number of n-digit numbers requiring 5 positive biquadrates in their representation as sum of biquadrates.
Original entry on oeis.org
1, 6, 60, 587, 7277, 91470, 1151734, 14116900, 166220264, 1888964884, 20910204634
Offset: 1
A186658
Total number of n-digit numbers requiring 6 positive biquadrates in their representation as sum of biquadrates.
Original entry on oeis.org
1, 6, 71, 877, 11437, 140179, 1567562, 16444269, 158993052, 1448222849, 12807964358
Offset: 1
A186660
Total number of n-digit numbers requiring 7 positive biquadrates in their representation as sum of biquadrates.
Original entry on oeis.org
1, 5, 77, 1018, 11712, 122460, 1107703, 8829638, 71681321, 638559445, 6064719750
Offset: 1
A186662
Total number of n-digit numbers requiring 8 positive biquadrates in their representation as sum of biquadrates.
Original entry on oeis.org
1, 5, 77, 975, 9457, 83959, 700406, 6220793, 60225898, 600223995, 6000225272
Offset: 1
A186664
Total number of n-digit numbers requiring 9 positive biquadrates in their representation as sum of biquadrates.
Original entry on oeis.org
1, 5, 72, 842, 7755, 68550, 614030, 6014243, 60013964, 600013863, 6000013912
Offset: 1
A186666
Total number of n-digit numbers requiring 10 positive biquadrates in their representation as sum of biquadrates.
Original entry on oeis.org
0, 6, 66, 740, 7064, 62754, 602728, 6002740, 60002625, 600002765, 6000002823
Offset: 1
A186668
Total number of n-digit numbers requiring 11 positive biquadrates in their representation as sum of biquadrates.
Original entry on oeis.org
0, 6, 64, 690, 6674, 60914, 600941, 6000995, 60000942, 600000942, 6000000909
Offset: 1
Showing 1-10 of 76 results.
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