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 A257892 Numbers n with property that A062234(n) = A062234(n+1) = A062234(n+2) = A062234(n+3). 7
 332, 878, 1999, 3949, 4524, 5953, 6576, 8676, 10068, 11840, 17107, 17208, 19034, 19525, 46771, 46828, 52767, 54567, 54927, 56879, 58695, 61748, 65926, 77168, 77676, 79722, 92775, 92823, 96099, 101607, 111007, 136141, 160095, 160418, 173404 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n) = A258432(m), where m such that A258383(m) = 4. - Reinhard Zumkeller, May 31 2015 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..110 EXAMPLE a(1) = A258437(A258432(4)) = 332. - Reinhard Zumkeller, May 31 2015 PROG (PARI) d(k) = 2*prime(k)-prime(k+1); isok(n) = (d(n) == d(n+1)) && (d(n+1) == d(n+2)) && (d(n+2) == d(n+3)); \\ Michel Marcus, May 29 2015 (Perl) use Math::Prime::Util::PrimeArray; tie my @prime, "Math::Prime::Util::PrimeArray"; sub d { 2*\$prime[\$_[0]-1] - \$prime[\$_[0]] } for (1..1e6) { my \$dk=d(\$_); say if d(\$_+1)==\$dk && d(\$_+2)==\$dk && d(\$_+3)==\$dk } # Dana Jacobsen, May 31 2015 (Perl) use ntheory ":all"; { my @prime; sub d { 2*\$prime[\$_[0]-1] - \$prime[\$_[0]] } sub list { my \$n=shift; @prime=@{primes(nth_prime(\$n+5))}; my @d=map{d(\$_)}1..4; my @list; for (1..\$n) { push @list, \$_ if \$d[0]==\$d[1] && \$d[0]==\$d[2] && \$d[0]==\$d[3]; @d=(@d[1..3], d(\$_+4)) } @list; } } say join ", ", list(1e6); # Dana Jacobsen, May 31 2015 (Haskell) a257892 n = a257892_list !! (n-1) a257892_list = map a258432 \$ filter ((== 4) . a258383) [1..] -- Reinhard Zumkeller, May 31 2015 CROSSREFS Subsequence of A257762 and A062234. Cf. A258383, A258432, A258437, A258469, A258449, A257892, A257951. Sequence in context: A097401 A250758 A114084 * A235020 A111690 A095199 Adjacent sequences:  A257889 A257890 A257891 * A257893 A257894 A257895 KEYWORD nonn AUTHOR Zak Seidov, May 14 2015 STATUS approved

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Last modified September 25 19:42 EDT 2020. Contains 337344 sequences. (Running on oeis4.)