A139054 Array read by rows: row n lists the first 4 primes with n digits.

2, 3, 5, 7, 11, 13, 17, 19, 101, 103, 107, 109, 1009, 1013, 1019, 1021, 10007, 10009, 10037, 10039, 100003, 100019, 100043, 100049, 1000003, 1000033, 1000037, 1000039, 10000019, 10000079, 10000103, 10000121, 100000007, 100000037, 100000039, 100000049

Offset: 1

Author

Omar E. Pol, Apr 08 2008

Keywords

• base
• nonn
• tabf

Comments

First differs from A000040 at a(9). - Omar E. Pol, Feb 13 2014

Examples

			Array begins:
    2,   3,   5,   7;
   11,  13,  17,  19;
  101, 103, 107, 109;
  ...
		

Crossrefs

Cf. A000040, A003617, A073914, A139052, A139053.

Programs

Mathematica

Flatten @ Table[ NextPrime[10^i, Range @ 4], {i, 0, 9}] (* Mikk Heidemaa, Jan 08 2023 *)

Formula

a(4n-3) = A003617(n). - Omar E. Pol, Feb 13 2014

Extensions

More terms from Michel Marcus, Feb 13 2014