A355091 Variant of A253028 using only prime numbers.

2, 3, 5, 2, 7, 11, 3, 2, 5, 13, 17, 19, 23, 7, 3, 2, 5, 11, 29, 31, 13, 7, 3, 2, 2, 3, 5, 11, 17, 37, 41, 19, 43, 47, 53, 59, 23, 13, 29, 61, 67, 31, 17, 7, 5, 3, 2, 5, 7, 11, 19, 37, 71, 73, 41, 23, 13, 11, 7, 3, 2, 2, 3, 5, 11, 13, 17, 29, 43, 79

Offset: 1

Author

Rémy Sigrist, Jun 19 2022

Keywords

• nonn
• tabf

Comments

See the examples in A253028 for a detailed illustration of how the array is constructed:

- the n-th term gives the length of the n-th row.

- if you remove the eventual leading and trailing term in each row, you get the prime numbers, in natural order,

- repeating this procedure with the remaining terms always yields the prime numbers, in natural order.

Examples

			The first terms / rows are:
  n   a(n)  n-th row
  --  ----  ------------------------------------------------------------
   1     2                               2, 3
   2     3                             5, 2, 7
   3     5                         11, 3, 2, 5, 13
   4     2                              17, 19
   5     7                     23, 7, 3, 2, 5, 11, 29
   6    11              31, 13, 7, 3, 2, 2, 3, 5, 11, 17, 37
   7     3                            41, 19, 43
   8     2                              47, 53
   9     5                        59, 23, 13, 29, 61
  10    13          67, 31, 17, 7, 5, 3, 2, 5, 7, 11, 19, 37, 71
  11    17  73, 41, 23, 13, 11, 7, 3, 2, 2, 3, 5, 11, 13, 17, 29, 43, 79
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10022
• Rémy Sigrist, PARI program

Crossrefs

Cf. A253028, A354576, A354577.

Programs

PARI

See Links section.