|
| |
|
|
A112789
|
|
Primes such that the sum of the predecessor and successor primes is divisible by 11.
|
|
15
| |
|
|
31, 43, 67, 109, 131, 139, 191, 617, 727, 881, 911, 937, 953, 991, 1049, 1289, 1381, 1429, 1543, 1571, 1619, 1657, 1693, 1721, 1723, 1777, 1783, 1871, 1979, 2251, 2311, 2341, 2377, 2441, 2531, 2579, 2837, 2953, 3061, 3221, 3257, 3557, 3559, 3631, 3673
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
FORMULA
| a(n) = prime(i) is in this sequence iff prime(i-1)+prime(i+1) = 0 mod 11. a(n) = A000040(i) is in this sequence iff A000040(i-1)+A000040(i+1) = 0 mod 11.
|
|
|
EXAMPLE
| a(1) = 31 because prevprime(31) + nextprime(31) = 29 + 37 = 66 = 11 * 6.
a(2) = 43 because prevprime(43) + nextprime(43) = 41 + 47 = 88 = 11 * 8.
a(3) = 67 because prevprime(67) + nextprime(67) = 61 + 71 = 132 = 11 * 12.
a(4) = 109 because prevprime(109) + nextprime(109) = 107 + 113 = 220 = 11 * 20.
|
|
|
MATHEMATICA
| Prime@ Select[Range[2, 515], Mod[Prime[ # - 1] + Prime[ # + 1], 11] == 0 &] (* Robert G. Wilson v *)
Transpose[Select[Partition[Prime[Range[550]], 3, 1], Divisible[First[#]+ Last[#], 11]&]][[2]] (* From Harvey P. Dale, Jul 22 2011 *)
|
|
|
CROSSREFS
| Cf. A000040, A112681, A112794, A112731, A112789, A112795, A112796, A112804, A112847, A112859, A113155, A113156, A113157, A113158.
Sequence in context: A139883 A060834 A060844 * A161615 A016108 A059898
Adjacent sequences: A112786 A112787 A112788 * A112790 A112791 A112792
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Jonathan Vos Post (jvospost3(AT)gmail.com), Jan 01 2006
|
|
|
EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(at)rgwv.com), Jan 05 2006
|
| |
|
|
