S000910


Left- or right-truncatable primes in base 9.

2, 3, 5, 7, 11, 19, 23, 29, 31, 41, 43, 47, 53, 59, 61, 67, 71, 79, 101, 103, 107, 173, 179, 181, 191, 193, 211, 223, 229, 233, 241, 263, 269, 281, 283, 347, 353, 367, 373, 383, 389, 431, 479, 509, 547, 557, 607, 641, 643, 647, 659, 677, 691, 701, 709, 719

1

S000910

These numbers must be converted to base 9 and then truncated. For instance, the number 101 is 122(9).

T. D. Noe, Plot of 1211 terms

T. D. Noe, Table of 1211 terms

See references in  A137812.

(Mma) b = 9; Clear[s]; n = 0; s[n] = Prime[Range[PrimePi[b-1]]]; While[cnt = 0; lst = Reap[Do[k = s[n][[i]]; Do[p = j*b^(n+1) + k; If[PrimeQ[p], Sow[p]; cnt++], {j, b-1}]; Do[p = b*k + j; If[PrimeQ[p], Sow[p]; cnt++], {j, b-1}], {i, Length[s[n]]}]]; cnt > 0, n++; s[n] = Union[lst[[2,1]]]]; t = s[0]; Do[t = Join[t, s[i]], {i, n}]; t

Cf. A137812 (base 10), S000911-S000916 (bases 8 to 3), S000917.

nonn,base,full

T. D. Noe, Jun 21 2016

© Tony D Noe 2014-2016