A348835 Triangle, read by rows, T(n, k) is the smallest term of A006005 strictly larger than abs(A006005(n) - A006005(k)).

1, 3, 1, 5, 3, 1, 7, 5, 3, 1, 11, 11, 7, 5, 1, 13, 11, 11, 7, 3, 1, 17, 17, 13, 11, 7, 5, 1, 19, 17, 17, 13, 11, 7, 3, 1, 23, 23, 19, 17, 13, 11, 7, 5, 1, 29, 29, 29, 23, 19, 17, 13, 11, 7, 1, 31, 29, 29, 29, 23, 19, 17, 13, 11, 3, 1, 37, 37, 37, 31, 29, 29, 23, 19, 17, 11, 7, 1

Offset

1,2

Links

Table of n, a(n) for n=1..78.

Raghavendra Bhat, An Abelian Loop for Non-Composites, arXiv:2110.14716 [math.GM], 2021.

Formula

T(n, n) = 1.

T(n, 1) = n.

Example

Triangle begins:
   1;
   3,  1;
   5,  3,  1;
   7,  5,  3,  1;
  11, 11,  7,  5, 1;
  13, 11, 11,  7, 3, 1;
  17, 17, 13, 11, 7, 5, 1;
  ...

Prog

(PARI) f(n) = prime(n)-(n==1); /* A006005 */
T(n, k) = {my(j=1, m = abs(f(n)-f(k))); while (f(j) < m, j++); f(j); }

Crossrefs

Cf. A006005 (1 and the odd primes).

Sequence in context: A084305 A347066 A099375 * A130301 A133601 A258207

Adjacent sequences: A348832 A348833 A348834 * A348836 A348837 A348838

Keyword

nonn,tabl

Author

Michel Marcus, Nov 01 2021

Status

approved