A359123 First differences of A068811, halved.

1, 1, 2, 3, 6, 6, 3, 3, 3, 6, 6, 3, 4, 8, 12, 18, 3, 6, 18, 6, 9, 12, 18, 15, 3, 3, 12, 9, 15, 6, 18, 6, 9, 6, 18, 6, 15, 9, 12, 3, 3, 15, 18, 12, 9, 6, 18, 6, 3, 18, 12, 12, 9, 6, 3, 3, 9, 3, 3, 7, 17, 9, 51, 6, 9, 6, 12, 21, 21, 3, 6, 27, 27, 30, 6, 27, 9, 21, 12, 36, 84, 6

Offset: 1

Author

N. J. A. Sloane, Dec 18 2022

Keywords

• nonn

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A068811, A359121, A359122.

Programs

Mathematica

1/2*Differences@ Select[Prime@ Range[300], PrimeQ[10^(1 + Floor@ Log10[#]) - #] &] (* Michael De Vlieger, Dec 18 2022 *)