|
| |
|
|
A085720
|
|
Start of a run of 7 successive numbers which when concatenated form a prime.
|
|
0
|
|
|
|
7, 37, 157, 185, 187, 271, 301, 355, 475, 485, 523, 533, 577, 611, 653, 661, 667, 731, 733, 755, 761, 791, 853, 911, 913, 937, 983, 1085, 1111, 1187, 1205, 1253, 1397, 1417, 1585, 1631, 1655, 1685, 1697, 1711, 1723, 1841, 1907, 1975, 2035, 2077, 2105, 2185
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
Concatenation of three and six successive numbers are always composite.
Primes as concatenation of two, four and five successive numbers are in A030458, A030471, A052087, A052088, A052089.
|
|
|
LINKS
|
Table of n, a(n) for n=1..48.
|
|
|
MATHEMATICA
|
f[n_] := FromDigits[ Flatten[ Table[ IntegerDigits[i], {i, n, n + 6}]]]; Select[ Range[2190], PrimeQ[ f[ # ]] & ]
|
|
|
CROSSREFS
|
Cf. A030458, A030471, A052087, A052088, A052089.
Sequence in context: A202119 A201083 A036678 * A201962 A269257 A269258
Adjacent sequences: A085717 A085718 A085719 * A085721 A085722 A085723
|
|
|
KEYWORD
|
easy,nonn,base
|
|
|
AUTHOR
|
Zak Seidov, Jun 27 2003
|
|
|
EXTENSIONS
|
Edited by Robert G. Wilson v, Jun 28 2003
Edited by Charles R Greathouse IV, Apr 24 2010
|
|
|
STATUS
|
approved
|
| |
|
|
