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 1-10 of 10 results.

A309385 Numbers which converge to 24547284284866560000000000 under repeated application of the powertrain map of A133500.

Original entry on oeis.org

6672898, 6689728, 7266898, 7289668, 8966728, 8972668, 23667289, 23668972, 23726689, 23728966, 23896672, 23897266, 26667288, 26668872, 26726688, 26728866, 26886672, 26887266, 29367289, 29368972, 29667287, 29668772, 29723689, 29726687, 29728766, 29728936, 29728993, 29729389, 29876672, 29877266, 29893672, 29897236, 29897293, 29899372, 29937289, 29938972
Offset: 1

Views

Author

Martin Renner, Jul 27 2019

Keywords

Examples

			6672898 -> 6^6*7^2*8^9*8 = 2454728428486656 -> 2^4*5^4*7^2*8^4*2^8*4^8*6^6*5^6 = 24547284284866560000000000.

Links

Crossrefs

Cf. A133500, A135384, A135385, A326733, A326734, A326735, A326736, A326737, A326738, A326739, A326740, A326741, A326742.

A326735 Numbers which converge to 2 under repeated application of the powertrain map of A133500.

Original entry on oeis.org

2, 21, 28, 36, 44, 62, 93, 102, 112, 122, 132, 142, 152, 162, 172, 182, 192, 202, 211, 227, 229, 247, 256, 258, 263, 264, 272, 281, 286, 293, 302, 317, 324, 336, 342, 344, 349, 353, 358, 361, 376, 382, 402, 417, 419, 427, 433, 434, 441, 446, 456, 497, 502, 552
Offset: 1

Views

Author

Martin Renner, Jul 22 2019

Keywords

Examples

			28 -> 2^8 = 256 -> 2^5*6 = 192 -> 1^9*2 = 2.

Crossrefs

Cf. A133500, A133501, A135384, A135385, A309385, A326733, A326734, A326736, A326737, A326738, A326739, A326740, A326741, A326742.

Programs

  • Python
    # change target for A326733-A326742, A135384, A309385
def powertrain(n):
  p, s = 1, str(n)
  if len(s)%2 == 1: s += '1'
  for b, e in zip(s[0::2], s[1::2]): p *= int(b)**int(e)
  return p
def aupto(limit, target=0):
  alst = []
  for n in range(1, limit+1):
    m, ptm = n, powertrain(n)
    while m != ptm: m, ptm = ptm, powertrain(ptm)
    if m == target: alst.append(n)
  return alst
print(aupto(552, target=2)) # Michael S. Branicky, Feb 21 2021

A326733 Numbers which converge to 0 under repeated application of the powertrain map of A133500.

Original entry on oeis.org

0, 26, 35, 37, 38, 39, 43, 46, 47, 48, 49, 54, 55, 56, 57, 58, 59, 64, 65, 66, 67, 68, 69, 72, 73, 74, 76, 77, 78, 79, 82, 84, 85, 86, 87, 88, 89, 94, 95, 96, 97, 98, 99, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 236, 237, 238, 239
Offset: 1

Views

Author

Martin Renner, Jul 22 2019

Keywords

Examples

			26 -> 2^6 = 64 -> 6^4 = 1296 -> 1^2*9^6 = 531441 -> 5^3*1^4*4^1 = 500 -> 5^0*0 = 0.

Crossrefs

Cf. A133500, A133501, A135384, A135385, A309385, A326734, A326735, A326736, A326737, A326738, A326739, A326740, A326741, A326742.

A326736 Numbers which converge to 3 under repeated application of the powertrain map of A133500.

Original entry on oeis.org

3, 31, 103, 113, 123, 133, 143, 153, 163, 173, 183, 193, 203, 303, 311, 403, 503, 603, 703, 803, 903, 1031, 1131, 1231, 1331, 1431, 1531, 1631, 1731, 1831, 1931, 2031, 3031, 3100, 3110, 3111, 3112, 3113, 3114, 3115, 3116, 3117, 3118, 3119, 3120, 3130, 3140
Offset: 1

Views

Author

Martin Renner, Jul 22 2019

Keywords

Examples

			31 -> 3^1 = 3.

Crossrefs

Cf. A133500, A133501, A135384, A135385, A309385, A326733, A326734, A326735, A326737, A326738, A326739, A326740, A326741, A326742.

A326737 Numbers which converge to 4 under repeated application of the powertrain map of A133500.

Original entry on oeis.org

4, 22, 41, 104, 114, 124, 134, 144, 154, 164, 174, 184, 194, 204, 212, 221, 249, 304, 404, 411, 429, 504, 604, 624, 704, 804, 904, 1022, 1041, 1122, 1141, 1222, 1241, 1322, 1341, 1422, 1441, 1522, 1541, 1622, 1641, 1722, 1741, 1822, 1841, 1922, 1941, 2022
Offset: 1

Views

Author

Martin Renner, Jul 22 2019

Keywords

Examples

			249 -> 2^4*9 = 144 -> 1^4*4 = 4.

Crossrefs

Cf. A133500, A133501, A135384, A135385, A309385, A326733, A326734, A326735, A326736, A326738, A326739, A326740, A326741, A326742.

A326738 Numbers which converge to 5 under repeated application of the powertrain map of A133500.

Original entry on oeis.org

5, 51, 53, 105, 115, 125, 135, 145, 155, 165, 175, 185, 195, 205, 305, 335, 345, 405, 455, 505, 511, 525, 527, 531, 537, 605, 692, 705, 745, 805, 875, 905, 925, 1051, 1053, 1151, 1153, 1251, 1253, 1351, 1353, 1451, 1453, 1551, 1553, 1651, 1653, 1751, 1753
Offset: 1

Views

Author

Martin Renner, Jul 22 2019

Keywords

Examples

			53 -> 5^3 = 125 -> 1^2*5 = 5.

Crossrefs

Cf. A133500, A133501, A135384, A135385, A309385, A326733, A326734, A326735, A326736, A326737, A326739, A326740, A326741, A326742.

A326739 Numbers which converge to 6 under repeated application of the powertrain map of A133500.

Original entry on oeis.org

6, 61, 106, 116, 126, 136, 146, 156, 166, 176, 186, 196, 206, 213, 306, 312, 406, 506, 606, 611, 706, 724, 746, 806, 906, 1061, 1161, 1261, 1361, 1461, 1561, 1661, 1761, 1861, 1961, 2061, 2131, 2272, 2596, 3061, 3121, 3765, 3863, 4061, 4172, 4572, 5061, 6061
Offset: 1

Views

Author

Martin Renner, Jul 22 2019

Keywords

Examples

			724 -> 7^2*4 = 196 -> 1^9*6 = 6.

Crossrefs

Cf. A133500, A133501, A135384, A135385, A309385, A326733, A326734, A326735, A326736, A326737, A326738, A326740, A326741, A326742.

A326740 Numbers which converge to 7 under repeated application of the powertrain map of A133500.

Original entry on oeis.org

7, 71, 75, 107, 117, 127, 137, 147, 157, 167, 177, 187, 197, 207, 307, 407, 507, 523, 543, 607, 707, 711, 723, 747, 751, 807, 907, 1071, 1075, 1171, 1175, 1271, 1275, 1371, 1375, 1471, 1475, 1571, 1575, 1671, 1675, 1771, 1775, 1871, 1875, 1971, 1975, 2071
Offset: 1

Views

Author

Martin Renner, Jul 22 2019

Keywords

Examples

			75 -> 7^5 = 16807 -> 1^6*8^0*7 = 7.

Crossrefs

Cf. A133500, A133501, A135384, A135385, A309385, A326733, A326734, A326735, A326736, A326737, A326738, A326739, A326741, A326742.

A326741 Numbers which converge to 8 under repeated application of the powertrain map of A133500.

Original entry on oeis.org

8, 23, 27, 33, 34, 81, 92, 108, 118, 128, 138, 148, 158, 168, 178, 188, 198, 208, 214, 222, 231, 248, 254, 262, 271, 287, 308, 319, 323, 329, 331, 333, 334, 341, 408, 412, 428, 432, 447, 459, 508, 608, 623, 632, 708, 748, 794, 808, 811, 822, 908, 913, 919, 921
Offset: 1

Views

Author

Martin Renner, Jul 22 2019

Keywords

Examples

			33 -> 3^3 = 27 -> 2^7 = 128 -> 1^2*8 = 8.

Crossrefs

Cf. A133500, A133501, A135384, A135385, A309385, A326733, A326734, A326735, A326736, A326737, A326738, A326739, A326740, A326742.

A326742 Numbers which converge to 9 under repeated application of the powertrain map of A133500.

Original entry on oeis.org

9, 25, 32, 52, 91, 109, 119, 129, 139, 149, 159, 169, 179, 189, 199, 209, 228, 234, 242, 251, 279, 295, 309, 313, 321, 337, 377, 409, 418, 422, 509, 515, 521, 539, 544, 609, 709, 809, 814, 835, 909, 911, 965, 1025, 1032, 1052, 1091, 1125, 1132, 1152, 1191
Offset: 1

Views

Author

Martin Renner, Jul 22 2019

Keywords

Examples

			25 -> 2^5 = 32 -> 3^2 = 9.

Crossrefs

Cf. A133500, A133501, A135384, A135385, A309385, A326733, A326734, A326735, A326736, A326737, A326738, A326739, A326740, A326741.

Programs

  • Python
    def powertrain(n):
    p, s = 1, str(n)
    if len(s)%2 == 1: s += '1'
    for b, e in zip(s[0::2], s[1::2]): p *= int(b)**int(e)
    return p
def aupto(limit, target=0):
    alst = []
    for n in range(1, limit+1):
        m, ptm = n, powertrain(n)
        while m != ptm: m, ptm = ptm, powertrain(ptm)
        if m == target: alst.append(n)
    return alst
print(aupto(1191, target=9)) # Michael S. Branicky, Sep 25 2021
Showing 1-10 of 10 results.

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

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