S000915


Left- or right-truncatable primes in base 4.

2, 3, 7, 11, 13, 23, 29, 31, 43, 47, 53, 59, 61, 107, 127, 151, 157, 173, 181, 191, 223, 239, 251, 383, 431, 479, 509, 607, 619, 631, 727, 751, 919, 941, 991, 1019, 2039, 2477, 2557, 2909, 3067, 3581, 3677, 3691, 3767, 3823, 3967, 4013, 4079, 4091, 6653, 7919

1

S000915

These numbers must be converted to base 4 and then truncated. For instance, the number 107 is 1223(4).

T. D. Noe, Plot of 69 terms

T. D. Noe, Table of 69 terms

See references in  A137812.

(Mma) b = 4; 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), S000910-S000916 (bases 9 to 3), S000917.

nonn,base,full

T. D. Noe, Jun 21 2016

© Tony D Noe 2014-2016