|
| |
|
|
A134971
|
|
Canyon primes.
|
|
11
| |
|
|
101, 313, 727, 757, 919, 929, 3023, 3203, 7027, 7057, 7127, 7207, 7237, 7247, 7307, 7417, 7457, 7507, 7517, 7537, 7547, 7607, 9029, 9049, 9059
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| Intersection of prime numbers and Canyon numbers ("Canyon primes"). This sequence is finite because A134970 is. There are 9237 Canyon primes (compare to 116505 Canyon numbers total). The largest Canyon prime (and last element of this sequence) is a(9237) = 98765432101456789.
|
|
|
LINKS
| Kellen Myers, Table of n, a(n) for n = 1..9237
|
|
|
FORMULA
| A000040 INTERSECT A134970.
|
|
|
EXAMPLE
| Illustration of 751367 as a Canyon prime:
. . . . . .
. . . . . .
7 . . . . 7
. . . . 6 .
. 5 . . . .
. . . . . .
. . . 3 . .
. . . . . .
. . 1 . . .
. . . . . .
|
|
|
MATHEMATICA
| S = {}; c = 1;
For[n = 1, n <= 9, n++,
L = 2 n - 1;
d = Join[Reverse[Range[1, n - 1]], Range[0, n - 1]];
If[Mod[n, 2] != 0 && n != 5,
For[j = 1, j < 2^L, j++,
Dig = d[[Map[#[[1]] &, Position[IntegerDigits[j, 2, L], 1]]]];
min = Min[Dig];
If[Length[Position[Dig, min]] == 1,
p = FromDigits[Join[{n}, Dig, {n}]];
If[PrimeQ[p], S = Append[S, p]];
];
];
];
];
|
|
|
CROSSREFS
| Cf. A000040, A134951, Primes in A134970.
Sequence in context: A139701 A195294 A142578 * A082770 A161907 A195855
Adjacent sequences: A134968 A134969 A134970 * A134972 A134973 A134974
|
|
|
KEYWORD
| nonn,base,fini,full
|
|
|
AUTHOR
| Omar E. Pol (info(AT)polprimos.com), Nov 25 2007
|
|
|
EXTENSIONS
| Mathematica, all terms (past 3203), more comments, etc. by Kellen Myers (Jan 18 2011).
|
| |
|
|
