A048847 Primes formed by concatenation of first k odd numbers.

13, 135791113151719, 135791113151719212325272931, 135791113151719212325272931333537394143454749515355575961636567

Offset

1,1

Comments

The next term (a(5)) has 93 digits. - Harvey P. Dale, Mar 05 2013

a(6) has 9725 digits (see A066811(6) or A046036(6)). - Michel Marcus, Jan 31 2014

References

R. W. Stephan, Factors and Primes in Two Smarandache Sequences, Smarandache Notions Journal, second edition, Vol. 9, No. 1-2, 1998, 5-11.

Links

Table of n, a(n) for n=1..4.

M. Fleuren, Smarandache Concatenated Odds.

Eric Weisstein's World of Mathematics, Consecutive Number Sequences

Mathematica

Select[Table[FromDigits[Flatten[IntegerDigits/@Range[1, 2n+1, 2]]], {n, 40}], PrimeQ] (* Harvey P. Dale, Mar 05 2013 *)

Crossrefs

Cf. A019519, A046036.

Sequence in context: A177224 A145234 A334634 * A093671 A257137 A134070

Adjacent sequences: A048844 A048845 A048846 * A048848 A048849 A048850

Keyword

nonn,base

Author

N. J. A. Sloane, Charles T. Le (charlestle(AT)yahoo.com)

Extensions

Edited by Charles R Greathouse IV, Apr 23 2010

Status

approved