|
|
A113157
|
|
Primes such that the sum of the predecessor and successor primes is divisible by 41.
|
|
15
|
|
|
283, 409, 739, 983, 1021, 2213, 2251, 2339, 2663, 2749, 3079, 3821, 3931, 4219, 4463, 4799, 4919, 5413, 5741, 6271, 6917, 7703, 7753, 7873, 8287, 8861, 9013, 10091, 10427, 10709, 11317, 11483, 12421, 12917, 13037, 13693, 13781, 14029, 14759
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
a(n) = prime(i) is in this sequence iff prime(i-1)+prime(i+1) = 0 mod 41. a(n) = A000040(i) is in this sequence iff A000040(i-1)+A000040(i+1) = 0 mod 41.
|
|
EXAMPLE
|
a(1) = 283 since prevprime(283) + nextprime(283) = 281 + 293 = 574 = 41 * 14.
a(2) = 409 since prevprime(409) + nextprime(409) = 401 + 419 = 820 = 41 * 20.
a(3) = 739 since prevprime(739) + nextprime(739) = 733 + 743 = 1476 = 41 * 36.
a(4) = 983 since prevprime(983) + nextprime(983) = 977 + 991 = 1968 = 41 * 48.
|
|
MATHEMATICA
|
Prime@Select[Range[2, 1766], Mod[Prime[ # - 1] + Prime[ # + 1], 41] == 0 &] (* Robert G. Wilson v *)
Transpose[Select[Partition[Prime[Range[2000]], 3, 1], Divisible[First[#] + Last[#], 41]&]][[2]] (* Harvey P. Dale, Jul 25 2012 *)
|
|
CROSSREFS
|
Cf. A000040, A112681, A112794, A112731, A112789, A112795, A112796, A112804, A112847, A112859, A113155, A113156, A113157, A113158.
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|