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A103601
Numbers k such that the string 10k is the decimal expansion of a prime number.
4
1, 3, 7, 9, 13, 19, 21, 31, 33, 39, 49, 51, 61, 63, 69, 87, 91, 93, 97, 103, 111, 133, 139, 141, 151, 159, 163, 169, 177, 181, 193, 211, 223, 243, 247, 253, 259, 267, 271, 273, 289, 301, 303, 313, 321, 331, 333, 337, 343, 357, 369, 391, 399, 427, 429, 433, 453
OFFSET
1,2
LINKS
EXAMPLE
1 is in the sequence because 101 is prime.
33 is in the sequence because 1033 is prime.
141 is in the sequence because 10141 is prime.
MATHEMATICA
A103601=Reap[For[n=1, n<10^3, If[PrimeQ[n+10^Floor[Log[10, 100n]]], Sow[n]]; n+=2]][[2, 1]] [From Zak Seidov, Dec 15 2008]
PROG
(Magma) [ n: n in [1..500] | IsPrime(Seqint(Intseq(n) cat [0, 1])) ];
CROSSREFS
Sequence in context: A107771 A364614 A215800 * A291344 A297002 A111250
KEYWORD
base,nonn
AUTHOR
Parthasarathy Nambi, Mar 23 2005
EXTENSIONS
More terms from Zak Seidov, Dec 15 2008
STATUS
approved