A036536
Smallest cube containing exactly n 9's.
Original entry on oeis.org
0, 729, 29791, 970299, 994011992, 997002999, 499999005953, 999700029999, 999940001199992, 999970000299999, 991023990975990999, 999997000002999999, 299243659909999996099, 999999700000029999999, 929999949497863992829999, 999100239990997599909999
Offset: 0
-
nsmall = Table[Infinity, 15];
For[i = 0, i <= 10^6, i++, n0 = Count[IntegerDigits[i^3], 9];
If[nsmall[[n0 + 1]] > i^3, nsmall[[n0 + 1]] = i^3]];
Cases[nsmall, ?NumberQ] (* _Robert Price, Mar 20 2020 *)
A048364
a(n) is the index of the smallest triangular number containing exactly n 9's.
Original entry on oeis.org
13, 44, 631, 1413, 28282, 76419, 282842, 1414213, 4471955, 31616419, 446313656, 1414001413, 6276925986, 44710913656, 44721356419, 632129732586, 527257052109, 14141923468538, 44698881216419, 199449241362306, 141421356237309, 4690415742340969, 42426404749855955, 44703449755024186, 1095435073375871053
Offset: 1
Cf.
A036526,
A048354,
A048355,
A048356,
A048357,
A048358,
A048359,
A048360,
A048361,
A048362,
A048363,
A048547.
-
nsmall = Table[Infinity, 20];
For[i = 0, i <= 10^6, i++, p = PolygonalNumber[i];
n0 = Count[IntegerDigits[p], 9];
If[nsmall[[n0]] > i, nsmall[[n0]] = i]];
ReplaceAll[nsmall, Infinity -> "?"] (* Robert Price, Mar 22 2020 *)
A036516
Smallest square containing exactly n 9's.
Original entry on oeis.org
9, 3969, 29929, 1999396, 299739969, 2909199969, 19299599929, 909995799969, 9499999990849, 999999202999696, 9969959993997969, 90949999999997329, 9199999971969929929, 199999969997999200969, 19997911999199999979409, 295191999919994299999969
Offset: 1
-
a[n_] := Block[{k=1}, While[DigitCount[k^2, 10, 9] != n, k++]; k^2]; Array[a, 6] (* Giovanni Resta, Jul 27 2018 *)
Showing 1-3 of 3 results.
Comments