A247900 First differences of A247681.

54, 36, 54, 72, 18, 18, 36, 36, 18, 18, 54, 36, 18, 36, 54, 36, 54, 18, 18, 18, 18, 54, 18, 54, 18, 36, 54, 18, 54, 18, 36, 18, 36, 54, 18, 18, 18, 18, 54, 18, 18, 18, 18, 18, 36, 36, 18, 18, 72, 18, 36, 36, 36, 18, 36, 54, 18, 18, 36, 18, 18, 18, 18, 18, 54, 36, 36, 18, 72, 18, 18, 72, 18, 36, 36, 18, 18, 18, 36, 90

Offset: 1

Author

Odimar Fabeny, Sep 26 2014

Keywords

• nonn
• easy

Comments

All terms have digital root equal to 9.

Links

• Odimar Fabeny, Table of n, a(n) for n = 1..9999 [first term removed by _Georg Fischer_, Sep 02 2020]

Crossrefs

Cf. A247681.

Programs

Mathematica

Differences[Select[Range[1,3500,18],!PrimeQ[#]&]] (* Harvey P. Dale, Apr 25 2018 *)

Extensions

First term 54 removed by Georg Fischer, Sep 02 2020