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A279204
Numbers whose decimal expansion is a concatenation of 4 consecutive increasing nonnegative numbers.
8
1234, 2345, 3456, 4567, 5678, 6789, 78910, 891011, 9101112, 10111213, 11121314, 12131415, 13141516, 14151617, 15161718, 16171819, 17181920, 18192021, 19202122, 20212223, 21222324, 22232425, 23242526, 24252627, 25262728, 26272829, 27282930, 28293031, 29303132, 30313233, 31323334
OFFSET
1,1
COMMENTS
Primes in this sequence are A030471. Are there infinitely many primes in the sequence? - Chai Wah Wu, Dec 17 2016
MATHEMATICA
A279204[n_] := FromDigits[Flatten[IntegerDigits[Range[n, n + 3]]]];
Array[A279204, 50] (* Paolo Xausa, Aug 26 2024 *)
PROG
(Python)
def A279204(n):
return int(str(n)+str(n+1)+str(n+2)+str(n+3)) # Chai Wah Wu, Dec 17 2016
CROSSREFS
Cf. A030471 (primes).
For concatenations of exactly k consecutive integers see A000027(k=1), A127421 (k=2), A001703 (k=3), A279204 (k=4). For 2 or more see A035333.
Sequence in context: A055616 A104971 A193492 * A091332 A210515 A122043
KEYWORD
nonn,easy,base
AUTHOR
N. J. A. Sloane, Dec 17 2016
STATUS
approved