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A035095 Smallest prime of form k*p(n) + 1, the arithmetical progressions of prime differences. +0
8
3, 7, 11, 29, 23, 53, 103, 191, 47, 59, 311, 149, 83, 173, 283, 107, 709, 367, 269, 569, 293, 317, 167, 179, 389, 607, 619, 643, 1091, 227, 509, 263, 823, 557, 1193, 907, 1571, 653, 2339, 347, 359, 1087, 383, 773, 3547, 797, 2111, 2677, 5449, 2749, 467 (list; graph; listen)
OFFSET

1,1

COMMENT

Note that both the terms of this sequence and differences are primes.

This is one possible generalization of "the least prime problem in special arithmetical progressions" when n in the nk+1 form is replaced by n-th prime number.

Smallest numbers m such that largest prime-factor of Phi[m]=p(n), the n-th prime seems to be also prime number and identical to n-th of A035095. See A068211, A068212, A065966: Min[x : A068211(x)=p(n)]=A035095(n); e.g. Phi[a(7)]=Phi[103]=2.3.17 of which 17=p(7) is the largest prime-factor,arising first here.

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

Index entries for sequences related to primes in arithmetic progressions

FORMULA

a(n) is the smallest prime such that greatest prime divisor of a(n)-1 is p(n), the n-th prime: a(n)=Min{p, A006530[p-1]=A000040(n)}

EXAMPLE

a(8) = 191 because in the p(8)k+1 = 19k+1 sequence 191 is the smallest prime.

PROGRAM

(PARI) for(n=1, 80, s=1; while((isprime(s)*s-1)%(prime(n))>0, s++); print1(s, ", "))

CROSSREFS

Cf. A034694, A006530, A006093, A035096, A000040, A019434, A058383.

Cf. A068211, A068212, A065966, A000010, A070844-A070858, A061092.

Sequence in context: A103798 A093361 A051202 this_sequence A066674 A125878 A126112

Adjacent sequences: A035092 A035093 A035094 this_sequence A035096 A035097 A035098

KEYWORD

nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu)

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Last modified November 29 12:46 EST 2009. Contains 167659 sequences.


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