A088264 Smallest number k > 0 such that prefixing k to the n-th quadruple in the set {(1,3,7,9), (11,13,17,19), (21,23,27,29), ...} yields all primes.

1, 189, 8, 94, 156, 32, 34, 18, 14, 1, 1653, 101, 2764, 99, 326, 715, 144, 1322, 4300, 768, 122, 67, 72, 500, 427, 3, 77, 22, 285, 119, 25, 294, 632, 55, 51, 3974, 217, 1230, 1022, 346, 1461, 260, 19, 9, 536, 463, 3, 299, 1, 69, 539, 1285, 1833, 116, 397, 3951

Offset

1,2

Comments

a(n) is the least k such that 10^A055642(n)*k+n is in A007811. - Robert Israel, Jun 18 2017

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(2) = 189 as 189 is the smallest number such that 18911, 18913, 18917 and 18919 are all prime.

Maple

f:= proc(n) local R, k, p;
R:= map(`+`, [1, 3, 7, 9], 10*(n-1));
p:= 10^(ilog10(R[1])+1);
for k from 1 do
  if map(t -> isprime(t+p*k), R) = [true, true, true, true] then return k fi
od
end proc:
map(f, [$1..60]); # Robert Israel, Jun 18 2017

Crossrefs

Cf. A007530, A007811, A055642.

Sequence in context: A089273 A035832 A065612 * A068557 A253024 A031901

Adjacent sequences: A088261 A088262 A088263 * A088265 A088266 A088267

Keyword

base,nonn

Author

Amarnath Murthy, Sep 28 2003

Extensions

Corrected and extended by Ray G. Opao, Mar 23 2005

More terms from David Wasserman, Jul 27 2005

Status

approved