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.

A059872 Solutions to the equation given in A059871, encoded as binary vectors and converted to decimal.

Original entry on oeis.org

1, 3, 5, 13, 21, 46, 51, 52, 78, 83, 84, 175, 181, 205, 210, 303, 309, 333, 338, 390, 392, 639, 698, 726, 728, 737, 822, 824, 846, 851, 852, 903, 905, 1143, 1145, 1197, 1202, 1226, 1232, 1311, 1322, 1328, 1350, 1352, 1409, 1562, 1571, 1572, 1601, 2539, 2540
Offset: 1

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Author

Antti Karttunen, Feb 05 2001

Keywords

Comments

The rows of this table have lengths given by A059871.
In binary encodings, the least significant bit (bit-0) stands for the factor of 1, the next bit (bit-1) stands for the factor of 2, bit-2 for the factor of 3, bit-3 for the factor of 5, etc., each bit being 0 if the corresponding factor is -1 and 1 if it is +1 (or +2 if the bit is the most significant bit of the code of odd length).
E.g. we have 2 = 2*1 -> 1 in binary, 3 = 1*2 + 1*1 -> 11 in binary, 5 = 2*3 - 1*2 + 1*1 -> 101 in binary, 7 = 1*5 + 1*3 - 1*2 + 1*1 -> 1101 in binary, 11 = 2*7 - 1*5 + 1*3 - 1*2 + 1*1 -> 10101 in binary. Function bin_prime_sum given in A059876 maps such encodings back to primes.

Examples

			Rows are:
  1;
  3;
  5;
  13;
  21;
  46,51,52;
  78,83,84;
  175,181,205,210;
  ...
		

Crossrefs

Programs

  • Maple
    map(op, primesums_primes_mult(16)); # primesums_primes_mult given in A059871.