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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.

A362463 Array of numbers read by upward antidiagonals: leading row lists the primes as they were in the 19th century (A008578); the following rows give absolute values of differences of previous row.

Original entry on oeis.org

1, 1, 2, 0, 1, 3, 1, 1, 2, 5, 0, 1, 0, 2, 7, 1, 1, 2, 2, 4, 11, 0, 1, 2, 0, 2, 2, 13, 1, 1, 2, 0, 0, 2, 4, 17, 0, 1, 2, 0, 0, 0, 2, 2, 19, 1, 1, 2, 0, 0, 0, 0, 2, 4, 23, 0, 1, 2, 0, 0, 0, 0, 0, 2, 6, 29, 1, 1, 0, 2, 2, 2, 2, 2, 2, 4, 2, 31, 0, 1, 0, 0, 2, 0, 2, 0, 2, 0, 4, 6, 37, 1, 1, 0, 0, 0, 2, 2, 0, 0, 2, 2, 2, 4, 41
Offset: 1

Views

Author

N. J. A. Sloane, May 08 2023

Keywords

Comments

The Gilbreath transform (cf. A362451) of A008578.
Analogous to A036262. The Gilbreath conjecture is that the initial terms of the rows are 1,(1,0)* = A135528.

Examples

			The array begins:
  1 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67
  1 1 2 2 4  2  4  2  4  6  2  6  4  2  4  6  6  2  6  4
  0 1 0 2 2  2  2  2  2  4  4  2  2  2  2  0  4  4  2  2
  1 1 2 0 0  0  0  0  2  0  2  0  0  0  2  4  0  2  0  2
  0 1 2 0 0  0  0  2  2  2  2  0  0  2  2  4  2  2  2  0
  1 1 2 0 0  0  2  0  0  0  2  0  2  0  2  2  0  0  2  2
  0 1 2 0 0  2  2  0  0  2  2  2  2  2  0  2  0  2  0  0
  1 1 2 0 2  0  2  0  2  0  0  0  0  2  2  2  2  2  0  0
  0 1 2 2 2  2  2  2  2  0  0  0  2  0  0  0  0  2  0  0
  1 1 0 0 0  0  0  0  2  0  0  2  2  0  0  0  2  2  0  0
The first few antidiagonals are:
  1,
  1, 2,
  0, 1, 3,
  1, 1, 2, 5,
  0, 1, 0, 2, 7,
  1, 1, 2, 2, 4, 11,
  0, 1, 2, 0, 2, 2, 13,
  1, 1, 2, 0, 0, 2, 4, 17,
  0, 1, 2, 0, 0, 0, 2, 2, 19,
  1, 1, 2, 0, 0, 0, 0, 2, 4, 23,
  0, 1, 2, 0, 0, 0, 0, 0, 2, 6, 29,
		

Crossrefs

Programs

  • Mathematica
    A362463[dmax_]:=With[{d=Reverse[NestList[Abs[Differences[#]]&,Join[{1},Prime[Range[dmax-1]]],dmax-1]]},Array[Diagonal[d,#]&,dmax,1-dmax]];A362463[20] (* Generates 20 antidiagonals *) (* Paolo Xausa, May 08 2023 *)