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A088606 Smallest number k such that concatenation of k and prime(n) is a prime, or 0 if no other number exists. a(1) = a(3) = 0. 3
0, 1, 0, 1, 2, 1, 3, 4, 2, 2, 1, 1, 2, 4, 3, 3, 3, 4, 1, 2, 1, 1, 2, 3, 1, 5, 1, 5, 1, 2, 4, 2, 2, 4, 11, 1, 4, 1, 3, 6, 2, 1, 3, 1, 5, 6, 4, 1, 5, 1, 5, 2, 4, 2, 3, 6, 2, 3, 1, 2, 1, 2, 1, 2, 3, 6, 3, 4, 2, 4, 6, 3, 1, 1, 6, 2, 2, 4, 12, 1, 5, 4, 5, 1, 1, 5, 3, 3, 3, 3, 2, 5, 1, 3, 1, 2, 17, 2, 1, 3, 3, 2, 5, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Subsidiary sequences: (set(1)) Index of the start of the first occurrence of a string of n consecutive 1's or 2's or 3's etc. (set (2)): a(n) = smallest prime such that concatenation of 1 with n successive primes starting from a(n) gives primes in each case. ( n primes are obtained.) Similarly for 2,3, etc. Conjecture: The subsidiary sequences are infinite.

LINKS

Table of n, a(n) for n=1..104.

CROSSREFS

Cf. A096915.

Sequence in context: A162598 A088208 A081878 * A140073 A333400 A131389

Adjacent sequences:  A088603 A088604 A088605 * A088607 A088608 A088609

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Oct 15 2003

EXTENSIONS

More terms from Ray Chandler, Oct 18 2003

STATUS

approved

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Last modified May 5 22:32 EDT 2021. Contains 343578 sequences. (Running on oeis4.)