A168417 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A168417

Primes q for which 1 concatenated with q^3 (A168327) is prime.

3, 13, 103, 109, 139, 163, 181, 211, 379, 457, 463, 1021, 1087, 1123, 1201, 1249, 1303, 1381, 1579, 1597, 1609, 1699, 1861, 1873, 1987, 2011, 2029, 2053, 2143, 2221, 2281, 2341, 2473, 2503, 2557, 2731, 2857, 3061, 3067, 3217, 3253, 3271, 3319, 3331, 3517

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

It is conjectured that this sequence is infinite.

REFERENCES

Harold Davenport, Multiplicative Number Theory, Springer-Verlag New-York 1980

Leonard E. Dickson: History of the Theory of numbers, vol. I, Dover Publications 2005

LINKS

Table of n, a(n) for n=1..45.

EXAMPLE

(1) "1 3^3"=10^2+3^3=127=prime(31) gives a(1)=3=prime(2)

(2) "1 103^3"=10^7+103^3=11092727=prime(732258) gives a(3)=103=prime(27)

MATHEMATICA

Select[Prime[Range[500]], PrimeQ[FromDigits[Join[{1}, IntegerDigits[ #^3]]]]&] (* Harvey P. Dale, Jan 21 2013 *)

CROSSREFS

A168147 Primes of the form p = 1 + 10*n^3 for a natural number n

A168327 Primes of concatenated form p= "1 n^3"

A168375 Natural numbers n for which the concatenation p= "1 n^3" is prime

Sequence in context: A268215 A323687 A338697 * A352170 A240167 A127004

Adjacent sequences: A168414 A168415 A168416 * A168418 A168419 A168420

KEYWORD

nonn,base

AUTHOR

Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Nov 25 2009

EXTENSIONS

Edited and extended by Charles R Greathouse IV, Apr 23 2010

STATUS

approved