A134794 Concatenation of next n composite numbers.

4, 68, 91012, 14151618, 2021222425, 262728303233, 34353638394042, 4445464849505152, 545556575860626364, 65666869707274757677, 7880818284858687889091

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..200

Mathematica

cc[x_]:=FromDigits[Flatten[IntegerDigits/@x]]; Module[{nn= 100, cmps, tr, len}, cmps = Select[Range[nn], CompositeQ]; len=Length[cmps]; tr = Floor[ (Sqrt[1+8 len]-1)/2]; cc/@TakeList[cmps, Range[tr]]] (* Harvey P. Dale, Sep 26 2021 *)

Crossrefs

Cf. A053067, A133013. Composite numbers: A002808.

Sequence in context: A174809 A363427 A125587 * A248027 A093852 A065573

Adjacent sequences: A134791 A134792 A134793 * A134795 A134796 A134797

Keyword

base,easy,nonn

Author

Omar E. Pol, Nov 26 2007

Status

approved