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.

A144175 Numbers of rank 2 in the poset of lunar numbers.

Original entry on oeis.org

7, 18, 28, 38, 48, 58, 68, 78, 80, 81, 82, 83, 84, 85, 86, 87, 88, 108, 119, 129, 139, 149, 159, 169, 179, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 208, 218, 229, 239, 249, 259, 269, 279, 289, 290, 291, 292, 293, 294, 295, 296, 297
Offset: 1

Views

Author

David Applegate, Marc LeBrun and N. J. A. Sloane, Aug 25 2010, corrected Oct 14 2010

Keywords

Links

Crossrefs

Cf. A087097, A133626, A161813, A144171, A144175, A171786, A171787, A171788, A171789, A171794, A171795, A171796, A191752, A191753.

A087984 9-ish numbers (A011539) which are not lunar primes (A087097).

Original entry on oeis.org

9, 119, 129, 139, 149, 159, 169, 179, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 229, 239, 249, 259, 269, 279, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 339, 349, 359, 369, 379, 389, 390, 391, 392, 393, 394, 395, 396
Offset: 1

Views

Author

David Applegate and N. J. A. Sloane, Oct 30 2003

Keywords

Comments

Three and four digit 9ish numbers are lunar primes iff the smallest digit is strictly smaller than the first and the last digit. This is no longer true from 10109 = 109 x 109 on (where x = lunar product).

Links

Crossrefs

Cf. A011539, A087097. A133626 and A134211 are subsequences.

Programs

Formula

A011539 \ A087097. - M. F. Hasler, Nov 19 2018

A134211 Numbers that are lunar products of exactly 3 lunar primes.

Original entry on oeis.org

1119, 1129, 1139, 1149, 1159, 1169, 1179, 1189, 1190, 1191, 1192, 1193, 1194, 1195, 1196, 1197, 1198, 1199, 1229, 1239, 1249, 1259, 1269, 1279, 1289, 1290, 1291, 1292, 1293, 1294, 1295, 1296, 1297, 1298, 1299, 1339, 1349, 1359, 1369, 1379, 1389, 1390
Offset: 1

Views

Author

N. J. A. Sloane, Aug 14 2010

Keywords

Comments

A subsequence of A087984.

Links

  • N. J. A. Sloane, Table of n, a(n) for n = 1..1140 [These are the distinct products of three two-digit primes]
  • D. Applegate, M. LeBrun and N. J. A. Sloane, Dismal Arithmetic [Note: we have now changed the name from "dismal arithmetic" to "lunar arithmetic" - the old name was too depressing]

Crossrefs

Cf. A087097, A087984, A133626.

A171004 Numbers which are the lunar product of lunar primes in more than one way.

Original entry on oeis.org

1119, 1129, 1139, 1149, 1159, 1169, 1179, 1189, 1191, 1192, 1193, 1194, 1195, 1196, 1197, 1198, 1199, 1219, 1319, 1419, 1519, 1619, 1719, 1819, 1911, 1912, 1913, 1914, 1915, 1916, 1917, 1918, 1919, 2191, 2229, 2239, 2249, 2259, 2269, 2279, 2289, 2292, 2293, 2294, 2295, 2296, 2297, 2298, 2299, 2329, 2429, 2529, 2629, 2729, 2829, 2911, 2922, 2923, 2924, 2925, 2926, 2927, 2928
Offset: 1

Views

Author

N. J. A. Sloane, Sep 01 2010

Keywords

Examples

			1119 = 19*109 = 19*19*19.
1129 = 19*129 = 29*109 = 19*19*29.

Links

Crossrefs

Cf. A087097, A133626, A169977.
Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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