A113932 (RSA-2048)-10^n = prime where RSA-2048 is the 617 decimal digit unfactored RSA challenge number.

107, 848, 871, 966, 1110

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..5.

Example

(RSA-2048)- 10^107 = prime

Mathematica

Position[PrimeQ[Table[ \
251959084756578934940271832400483985714292821262040320277771378360436620207075\
955562640185258807844069182906412495150821892985591491761845028084891200728449\
926873928072877767359714183472702618963750149718246911650776133798590957000973\
304597488084284017974291006424586918171951187461215151726546322822168699875491\
824224336372590851418654620435767984233871847744479207399342365848238242811981\
638150106748104516603773060562016196762561338441436038339044149526344321901146\
575444541784240209246165157233507787077498171257724679629263863563732899121548\
31438167899885040445364023527381951378636564391212010397122822120720357 - \
10^n, {n, 1617}]], True]

Prog

(PARI) \\ Set N to RSA-2048
for(n=1, 617, if(ispseudoprime(N-10^n), print1(n", ")))

Crossrefs

Sequence in context: A183057 A059258 A212377 * A357551 A250154 A250155

Adjacent sequences: A113929 A113930 A113931 * A113933 A113934 A113935

Keyword

nonn,base,fini,full

Author

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

Status

approved