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A262571
Concatenation of the numbers from 2 to n.
16
2, 23, 234, 2345, 23456, 234567, 2345678, 23456789, 2345678910, 234567891011, 23456789101112, 2345678910111213, 234567891011121314, 23456789101112131415, 2345678910111213141516, 234567891011121314151617, 23456789101112131415161718, 2345678910111213141516171819
OFFSET
2,1
MATHEMATICA
Table[FromDigits[Flatten[IntegerDigits[Range[2, n]]]], {n, 2, 19}] (* Robert Price, Oct 28 2018 *)
PROG
(Magma) [Seqint(Reverse(&cat[Reverse(Intseq(k)): k in [2..n]])): n in [2..20]]; // Vincenzo Librandi, Oct 29 2018
(Python)
def a(n): return int("".join(map(str, range(2, n+1))))
print([a(n) for n in range(2, 20)]) # Michael S. Branicky, Feb 23 2021
CROSSREFS
For primes in this sequence see A089987.
See A262300 for more about this problem.
Sequence in context: A088094 A112782 A093672 * A283560 A159902 A301339
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Sep 25 2015
STATUS
approved