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.

A375765 Square array read by antidiagonals in ascending order T(n,k), n > 1 and k > 0, representing the least prime p that starts a run of exactly k consecutive primes, all having the same sum of digits in base n > 1, or -1 if no such number exists.

Original entry on oeis.org

2, 2, 3, 2, 11, 7, 2, 23, 7, 167, 2, 7, 151, 5, 941, 2, 139, 479, 1901, 1019, 6299, 2, 23, 8543, 467, 12823, 1013, 6287, 2, 293, 151, 123239, 463, 102811, 4391, 150287, 2, 89, 23929, 251, 2350349, 15667, 369991, 8849, 866087, 2, 523, 1823, 370247, 1747, 24370007
Offset: 2

Views

Author

Jean-Marc Rebert, Aug 27 2024

Keywords

Examples

			T(2,3) = 7, because the 3 consecutive primes 7 = 111_2, 11 = 1011 and 13 = 1101_2 have all the same sum of digits in base 2, and no lesser number has this property.
The upper left square of the table begins at T(2,1):
  2   3    7    167     941     6299 ...
  2  11    7      5    1019     1013 ...
  2  23  151   1901   12823   102811 ...
  2   7  479    467     463    15667 ...
  2 139 8543 123239 2350349 24370007 ...
  2  23  151    251    1747     1741 ...
... ...  ...    ...     ...      ... ...
		

Crossrefs

Cf. A071613.