A362036 The prime indices of A362034.

1, 1, 1, 1, 3, 1, 1, 4, 4, 1, 1, 5, 7, 5, 1, 1, 6, 10, 10, 6, 1, 1, 7, 14, 17, 14, 7, 1, 1, 8, 18, 27, 27, 18, 8, 1, 1, 9, 23, 39, 47, 39, 23, 9, 1, 1, 10, 28, 54, 75, 75, 54, 28, 10, 1, 1, 11, 33, 72, 115, 135, 115, 72, 33, 11, 1, 1, 12, 40, 95, 167, 222, 222, 167, 95, 40, 12, 1

Offset

0,5

Links

Table of n, a(n) for n=0..77.

Formula

T(n,k) = A000720(A362034(n,k)).

Example

Triangle begins:
      k=0  1  2  3  4
  n=0:  1;
  n=1:  1, 1;
  n=2:  1, 3, 1;
  n=3:  1, 4, 4, 1;
  n=4:  1, 5, 7, 5, 1;
  n=5:  ...

Mathematica

T[n_, 0] := T[n, n] = 2; T[n_, k_] := T[n, k] = NextPrime[T[n - 1, k - 1] + T[n - 1, k] - 1]; Table[PrimePi@ T[n, k], {n, 0, 11}, {k, 0, n}]] // Flatten (* Michael De Vlieger, Apr 06 2023 *)

Prog

(PARI) t(n, k) = if (n==0, 2, if (k==0, 2, if (k==n, 2, nextprime(t(n-1, k-1) + t(n-1, k))))); \\ A362034
T(n, k) = primepi(t(n, k)); \\ Michel Marcus, Apr 07 2023

Crossrefs

Cf. A000720, A362034.

Sequence in context: A205117 A077228 A049687 * A132735 A028262 A173117

Adjacent sequences: A362033 A362034 A362035 * A362037 A362038 A362039

Keyword

nonn,tabl

Author

Jack Braxton, Apr 05 2023

Status

approved