cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A172419 Numbers k that have measure of smoothness J larger than 4, where J = log(k)/log(rad(k)) and rad(k) is the product of the distinct prime divisors of k (A007947).

Original entry on oeis.org

32, 64, 128, 243, 256, 512, 729, 1024, 1458, 1536, 1728, 1944, 2048, 2187, 2304, 2592, 2916, 3072, 3125, 3456, 3888, 4096, 4374, 4608, 5184, 5832, 6144, 6561, 6912, 7776, 8192, 8748, 9216, 10240, 10368, 11664, 12288, 12500, 12800, 13122, 13824, 15552
Offset: 1

Views

Author

Artur Jasinski, Feb 02 2010

Keywords

Comments

Subsequence of A049094 and A172418.

Crossrefs

Programs

  • Mathematica
    aa = {}; Do[kk = FactorInteger[c]; nn = 1; Do[nn = nn*kk[[n]][[1]], {n, 1, Length[kk]}]; If[Log[c]/Log[nn] > 4, AppendTo[aa, c]], {c, 2, 10000}]; aa

A172420 Numbers k that have measure of smoothness J larger than 5, where J = log(k)/log(rad(k)) and rad(k) is the product of the distinct prime divisors of k (A007947).

Original entry on oeis.org

64, 128, 256, 512, 729, 1024, 2048, 2187, 4096, 6561, 8192, 8748, 9216, 10368, 11664, 12288, 13122, 13824, 15552, 15625, 16384, 17496, 18432, 19683, 20736, 23328, 24576, 26244, 27648, 31104, 32768, 34992, 36864, 39366, 41472, 46656, 49152
Offset: 1

Views

Author

Artur Jasinski, Feb 02 2010

Keywords

Comments

This sequence is a subsequence of A049094, A172418, and A172419.

Crossrefs

Programs

  • Mathematica
    aa = {}; Do[kk = FactorInteger[c]; nn = 1; Do[nn = nn*kk[[n]][[1]], {n, 1, Length[kk]}]; If[Log[c]/Log[nn] > 5, AppendTo[aa, c]], {c, 2, 10000}]; aa
    Select[Range[2,50000],Log[Times@@FactorInteger[#][[All,1]],#]>5&] (* Harvey P. Dale, Apr 30 2018 *)

A172421 Numbers k that have measure of smoothness J larger than 6, where J = log(k)/log(rad(k)) and rad(k) is the product of the distinct prime divisors of k (A007947).

Original entry on oeis.org

128, 256, 512, 1024, 2048, 2187, 4096, 6561, 8192, 16384, 19683, 32768, 49152, 52488, 55296, 59049, 62208, 65536, 69984, 73728, 78125, 78732, 82944, 93312, 98304, 104976, 110592, 118098, 124416, 131072, 139968, 147456, 157464, 165888, 177147, 186624, 196608
Offset: 1

Views

Author

Artur Jasinski, Feb 02 2010

Keywords

Comments

This sequence is a subsequence of A049094, A172418, A172419, and A172420.

Crossrefs

Programs

  • Mathematica
    aa = {}; Do[kk = FactorInteger[c]; nn = 1; Do[nn = nn*kk[[n]][[1]], {n, 1, Length[kk]}]; If[Log[c]/Log[nn] > 6, AppendTo[aa, c]], {c, 2, 10000}]; aa

Extensions

More terms from Amiram Eldar, Mar 10 2020

A172422 Numbers k that have measure of smoothness J larger than 7, where J = log(k)/log(rad(k)) and rad(k) is the product of the distinct prime divisors of k (A007947).

Original entry on oeis.org

256, 512, 1024, 2048, 4096, 6561, 8192, 16384, 19683, 32768, 59049, 65536, 131072, 177147, 262144, 294912, 314928, 331776, 354294, 373248, 390625, 393216, 419904, 442368, 472392, 497664, 524288, 531441, 559872, 589824, 629856, 663552, 708588, 746496, 786432
Offset: 1

Views

Author

Artur Jasinski, Feb 02 2010

Keywords

Comments

This sequence is a subsequence of A049094, A172418, A172419, A172420, and A172421.

Crossrefs

Programs

  • Mathematica
    aa = {}; Do[kk = FactorInteger[c]; nn = 1; Do[nn = nn*kk[[n]][[1]], {n, 1, Length[kk]}]; If[Log[c]/Log[nn] > 7, AppendTo[aa, c]], {c, 2, 10000}]; aa

Extensions

More terms from Amiram Eldar, Mar 10 2020
Showing 1-4 of 4 results.