A139053 Array read by rows: row n lists the first 3 primes with n digits.

2, 3, 5, 11, 13, 17, 101, 103, 107, 1009, 1013, 1019, 10007, 10009, 10037, 100003, 100019, 100043, 1000003, 1000033, 1000037, 10000019, 10000079, 10000103, 100000007, 100000037, 100000039, 1000000007, 1000000009, 1000000021, 10000000019, 10000000033, 10000000061

Offset: 1

Author

Omar E. Pol, Apr 08 2008

Keywords

• base
• nonn
• tabf

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..3000

Crossrefs

Cf. A000040, A003617, A073914, A139052, A139054.

Programs

Mathematica

np[n_]:=Module[{a=NextPrime[10^n]},{a,NextPrime[a], NextPrime[NextPrime[ a]]}]; Flatten[Array[np,12,0]] (* Harvey P. Dale, Dec 14 2011 *)
Flatten@Array[NextPrime[10^#,{1,2,3}]&,12,0] (* Giorgos Kalogeropoulos, May 06 2019 *)

Python

from sympy import nextprime
def auptodigs(maxdigits):
  alst = []
  for n in range(1, maxdigits+1):
    p1 = nextprime(10**(n-1))
    p2 = nextprime(p1)
    p3 = nextprime(p2)
    alst.extend([p1, p2, p3])
  return alst
print(auptodigs(11)) # Michael S. Branicky, May 07 2021

Extensions

More terms from Max Alekseyev, Dec 12 2011

a(32) and beyond from Michael S. Branicky, May 07 2021