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.

A060442 Triangle T(n,k), n >= 0, in which n-th row (for n >= 3) lists prime factors of Fibonacci(n) (see A000045), without repetition.

Original entry on oeis.org

0, 1, 1, 2, 3, 5, 2, 13, 3, 7, 2, 17, 5, 11, 89, 2, 3, 233, 13, 29, 2, 5, 61, 3, 7, 47, 1597, 2, 17, 19, 37, 113, 3, 5, 11, 41, 2, 13, 421, 89, 199, 28657, 2, 3, 7, 23, 5, 3001, 233, 521, 2, 17, 53, 109, 3, 13, 29, 281, 514229, 2, 5, 11, 31, 61, 557, 2417, 3, 7, 47, 2207, 2, 89
Offset: 0

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Author

N. J. A. Sloane, Apr 07 2001

Keywords

Comments

Rows have irregular lengths.
T(n,k) = A027748(A000045(n),k), k = 1 .. A022307(n). - Reinhard Zumkeller, Aug 30 2014

Examples

			Triangle begins:
     0;
     1;
     1;
     2;
     3;
     5;
     2;
    13;
     3,   7;
     2,  17;
     5,  11;
    89;
     2,   3;
   233;
    13,  29;
     2,   5, 61;
     3,   7, 47;
  1597;
     2,  17, 19;
    37, 113;
     3,   5, 11, 41;
   ...
		

Crossrefs

Cf. A027748, A022307 (row lengths for n>2), A001221.

Programs

  • Haskell
    a060442 n k = a060442_tabf !! n !! k
    a060442_row n = a060442_tabf !! n
    a060442_tabf = [0] : [1] : [1] : map a027748_row (drop 3 a000045_list)
    -- Reinhard Zumkeller, Aug 30 2014
  • Maple
    with(numtheory): with(combinat): for i from 3 to 50 do for j from 1 to nops(ifactors(fibonacci(i))[2]) do printf(`%d,`, ifactors(fibonacci(i))[2][j][1]) od: od:

Extensions

More terms from James Sellers, Apr 09 2001