A113934 (RSA-704) + 10^n = prime where RSA-704 is the 212 decimal digit unfactored RSA challenge number.

206, 356, 1274, 1528, 1568, 2402

Offset

1,1

Comments

This sequence shows that the difference between a composite number and a prime rests on the modification of a single decimal digit of the given composite integer.

Links

Table of n, a(n) for n=1..6.

Example

(RSA-704)+ 10^206 is prime.

Mathematica

Position[PrimeQ[Table[ \
740375634795617128280467960974295731425931888892312890849362326389727650340282\
662768919964196251178439958943305021275853701189680982867331732731089309005525\
05116877063299072396380786710086096962537934650563796359 + 10^n, {n, 2000}]], \
True]

Prog

(PARI) \\ Set N to RSA-704
for(n=1, 1e4, if(ispseudoprime(N+10^n), print1(n", "))) \\ Charles R Greathouse IV, Oct 05 2011

Crossrefs

Sequence in context: A025343 A222619 A252270 * A260101 A113490 A054007

Adjacent sequences: A113931 A113932 A113933 * A113935 A113936 A113937

Keyword

nonn

Author

Joao da Silva (zxawyh66(AT)yahoo.com), Jan 30 2006

Extensions

a(6) from Charles R Greathouse IV, Oct 05 2011

Status

approved