A377173 Rectangular array, by antidiagonals: (row 1) = r(1) = A000040 (primes); (row n) = r(n) = prime(r(n-1)) for n>=1.

2, 3, 3, 5, 5, 5, 7, 11, 11, 11, 11, 17, 31, 31, 31, 13, 31, 59, 127, 127, 127, 17, 41, 127, 277, 709, 709, 709, 19, 59, 179, 709, 1787, 5381, 5381, 5381, 23, 67, 277, 1063, 5381, 15299, 52711, 52711, 52711

Offset

1,1

Links

Table of n, a(n) for n=1..45.

Formula

A049076(n) = number of appearances of prime(n).

Example

corner:
   2     3      5       7      11       13       17
   3     5     11      17      31       41       59
   5    11     31      59     127      179      277
  11    31    127     277     709     1063     1787
  31   127    709    1787    5381     8527    15299
 127   709   5381   15299   52711    87803   167449
 709  5381  52711  167449  648391  1128889  2269733

Mathematica

r[0] = Range[16];
r[n_] := r[n] = Prime[r[n - 1]]
Grid[Table[r[n], {n, 1, 6}]]  (* array *)
p[n_, k_] := r[n][[k]];
Table[p[n - k + 1, k], {n, 9}, {k, n, 1, -1}] // Flatten  (* sequence *)

Crossrefs

Cf. A000040 (row 1), A007097 (column 1), A006450 (row 2), A038580 (row 3), A058009 (principal diagonal), A049076, A114537, A377181.

Sequence in context: A036703 A306253 A117629 * A081165 A289749 A087172

Adjacent sequences: A377170 A377171 A377172 * A377174 A377175 A377176

Keyword

nonn,tabl

Author

Clark Kimberling, Oct 19 2024

Status

approved