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.

A036261 Triangle of numbers arising from Gilbreath's conjecture: successive absolute differences of primes (read by antidiagonals upwards, omitting the initial row of primes).

Original entry on oeis.org

1, 1, 2, 1, 0, 2, 1, 2, 2, 4, 1, 2, 0, 2, 2, 1, 2, 0, 0, 2, 4, 1, 2, 0, 0, 0, 2, 2, 1, 2, 0, 0, 0, 0, 2, 4, 1, 2, 0, 0, 0, 0, 0, 2, 6, 1, 0, 2, 2, 2, 2, 2, 2, 4, 2, 1, 0, 0, 2, 0, 2, 0, 2, 0, 4, 6, 1, 0, 0, 0, 2, 2, 0, 0, 2, 2, 2, 4, 1, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 2, 2, 1, 0, 0, 0, 0, 0, 2, 2, 2, 2, 0, 0, 2, 4
Offset: 1

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Comments

A variant of A036262, which is the main entry for this array.

Examples

			Table begins (conjecture is leading term is always 1):
  2 3 5 7 11 13 17 19 23 ...
  1 2 2 4  2  4  2  4 ...
  1 0 2 2  2  2  2 ...
  1 2 0 0  0, 0 ...
  1 2 0 0  0 ...
  1 2 0 0 ...
  ...
		

References

  • R. K. Guy, Unsolved Problems Number Theory, A10.
  • C. A. Pickover, The Math Book, Sterling, NY, 2009; see p. 410.

Crossrefs

Programs

  • Mathematica
    max = 15; triangle = Rest[ NestList[ Abs[ Differences[#] ]& , Prime[ Range[max] ], max] ]; Flatten[ Table[ triangle[[n-k+1, k]], {n, 1, max-1}, {k, 1, n}]] (* Jean-François Alcover, Jan 23 2012 *)

Extensions

More terms from Naohiro Nomoto, May 22 2001