A397051 a(n) is the number of n-digit terms in A397050.

4, 5, 63, 443, 2725, 20243, 167982, 1496045

Offset

1,1

Links

Table of n, a(n) for n=1..8.

Formula

Conjecture: lim_{n->oo} a(n+1)/a(n) = 10.

Mathematica

nmax=4; a={2}; For[k=3, k<=10^nmax-1, k++, If[AllTrue[a, Mod[DigitSum[k], #]!=0 &] && PrimeQ[k], AppendTo[a, k]]]; Table[Length[Select[a, IntegerLength[#]==i &]], {i, nmax}]

Crossrefs

Cf. A397050.

Sequence in context: A341575 A013331 A226145 * A042425 A109348 A192084

Adjacent sequences: A397047 A397048 A397050 * A397052 A397053 A397054

Keyword

nonn,base,hard,more

Author

Stefano Spezia, Jun 14 2026

Status

approved