A256113 Table read by rows: T(1,1) = 1, for n > 1: row n = union of distinct prime factors occurring in terms of n-th row of Pascal's triangle, cf. A007318.

1, 2, 3, 2, 3, 2, 5, 2, 3, 5, 3, 5, 7, 2, 5, 7, 2, 3, 7, 2, 3, 5, 7, 2, 3, 5, 7, 11, 2, 3, 5, 7, 11, 2, 3, 5, 11, 13, 2, 3, 7, 11, 13, 3, 5, 7, 11, 13, 2, 3, 5, 7, 11, 13, 2, 5, 7, 11, 13, 17, 2, 3, 5, 7, 11, 13, 17, 2, 3, 7, 11, 13, 17, 19, 2, 3, 5, 11, 13

Offset

1,2

Links

Reinhard Zumkeller, b-file  >>Rows n = 1..1000 of triangle, flattened

Index entries for triangles and arrays related to Pascal's triangle

Example

.  n |   T(n,k)   |                A001142(n) | A007318(n,0..n)
. ---+------------+---------------------------+-------------------------
.  1 | 1          |                         1 | 1  1
.  2 | 2          |                         2 | 1  2  1
.  3 | 3          |                         9 | 1  3  3   1
.  4 | 2 3        |                        96 | 1  4  6   4   1
.  5 | 2 5        |                      2500 | 1  5 10  10   5   1
.  6 | 2 3 5      |                    162000 | 1  6 15  20  15   6   1
.  7 | 3 5 7      |                  26471025 | 1  7 21  35  35  21   7   1
.  8 | 2 5 7      |               11014635520 | 1  8 28  56  70  56  28 ...
.  9 | 2 3 7      |            11759522374656 | 1  9 36  84 126 126  84 ...
. 10 | 2 3 5 7    |         32406091200000000 | 1 10 45 120 210 252 210 ...
. 11 | 2 3 5 7 11 |     231627686043080250000 | 1 11 55 165 330 462 462 ...
. 12 | 2 3 5 7 11 | 4311500661703860387840000 | 1 12 66 220 495 792 924 ...

Prog

(Haskell)
a256113 n k = a256113_tabf !! (n-1) !! (n-1)
a256113_row n = a256113_tabf !! (n-1)
a256113_tabf = map a027748_row $ tail a001142_list

Crossrefs

Cf. A007318, A027748, A001142, A004788 (row lengths), A056606 (row products).

Sequence in context: A369690 A166985 A046215 * A256368 A057019 A084740

Adjacent sequences: A256110 A256111 A256112 * A256114 A256115 A256116

Keyword

nonn,tabf

Author

Reinhard Zumkeller, Mar 16 2015

Status

approved