A045507 Concatenate powers of 2.

1, 12, 124, 1248, 124816, 12481632, 1248163264, 1248163264128, 1248163264128256, 1248163264128256512, 12481632641282565121024, 124816326412825651210242048, 1248163264128256512102420484096, 12481632641282565121024204840968192, 1248163264128256512102420484096819216384

Offset

0,2

References

A. Murthy, Smarandache Notions Journal, Vol. 11 N. 1-2-3 Spring 2000. [Felice Russo, Nov 15 1999]

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..80

Example

a(2) = 124 because it is the concatenation of 2^0, 2^1 and 2^2.

Mathematica

Join[{1}, FromDigits/@Flatten/@IntegerDigits/@Flatten/@Rest[FoldList[List, {1}, 2^Range[25]]]] (* Vincenzo Librandi, Aug 10 2017 *)

Prog

(Magma) [Seqint(Reverse(&cat[Reverse(Intseq(2^k)): k in [0..n]])): n in [0..17]]; // Vincenzo Librandi, Aug 10 2017

Crossrefs

Cf. A000079, A007908.

Sequence in context: A039680 A332690 A016134 * A288350 A331396 A209041

Adjacent sequences: A045504 A045505 A045506 * A045508 A045509 A045510

Keyword

nonn,base

Author

Jeff Burch

Status

approved