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A034592
Cycle of 2 steps possible for 'concatenate a(n) and nextprime(a(n)) is a prime'.
2
0, 36, 150, 284, 464, 467, 525, 584, 644, 777, 855, 941, 1058, 1120, 1179, 1362, 1788, 1855, 2368, 2520, 2547, 2550, 2576, 2743, 2988, 3063, 3273, 3339, 3410, 3930, 4054, 4370, 4739, 4843, 4910, 5253, 5445, 5550, 5671, 5967, 6512, 6721, 6987, 7131, 7216
OFFSET
0,2
EXAMPLE
a(n)=777 -> nextprime(a(n)) is 787 so '777787' is prime (=step 1); a(n2)=777787 -> nextprime(a(n2)) is 777817 so '777787777817' is prime (=step 2).
CROSSREFS
Sequence in context: A203753 A039495 A263120 * A160754 A275496 A117511
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Oct 15 1998
STATUS
approved