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 A178216 a(n) = prime(A178215(n)) mod prime(n). 1
 1, 1, 4, 1, 10, 12, 1, 1, 22, 27, 1, 32, 10, 33, 27, 24, 1, 24, 8, 48, 72, 55, 39, 69, 44, 22, 16, 105, 44, 56, 14, 76, 87, 129, 22, 138, 85, 50, 82, 130, 69, 93, 18, 60, 135, 170, 105, 110, 225, 44 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS a(n) is the last residue modulo prime(n) in the minimal set of the first primes which contains all residues modulo prime(n). Build the smallest set {prime(1), prime(2), ..., prime(k)} of the first k consecutive primes such that the set {prime(1) mod prime(n), prime(2) mod prime(n), ..., prime(k) mod prime(n)} contains all residues {0, 1, 2, ..., prime(n)-1}. Then a(n) = prime(k) mod prime(n). - R. J. Mathar, Oct 25 2010 LINKS EXAMPLE If n=3, then prime(n)=5 and {2,3,5,7,11,13,17,19} is the minimal set of the first primes which contains all residues modulo 5. We have consecutive residues {2,3,0,2,1,3,2,4}. Therefore a(3)=4. MAPLE A178216 := proc(n) local p, k, modP, i ; p := ithprime(n) ; for k from 1 do modP := [seq( ithprime(j) mod p, j=1..k)] ; {seq(i, i=0..p-1)} minus convert(modP, set) ; if % = {} then return op(-1, modP) ; end if; end do: end proc: seq(A178216(n), n=1..50) ; # R. J. Mathar, Oct 25 2010 CROSSREFS Cf. A000040, A178215. Sequence in context: A213765 A182971 A062145 * A307529 A019213 A019128 Adjacent sequences:  A178213 A178214 A178215 * A178217 A178218 A178219 KEYWORD nonn AUTHOR Vladimir Shevelev, May 22 2010 EXTENSIONS a(10) corrected, more terms appended by R. J. Mathar, Oct 25 2010 Name corrected by Jon E. Schoenfield, May 10 2019 STATUS approved

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Last modified February 17 21:35 EST 2020. Contains 332006 sequences. (Running on oeis4.)