login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A239634 Initial digits of semiprimes in decimal representation. 3
4, 6, 9, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 5, 5, 5, 5, 6, 6, 6, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(n) = A000030(A001358(n)).

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

MATHEMATICA

First[IntegerDigits[#]]&/@Select[Range[300], PrimeOmega[#]==2&] (* Harvey P. Dale, Jul 24 2017 *)

PROG

(Haskell)

a239634 = a000030 . a001358

CROSSREFS

Cf. A239639 (run lengths), A106146 (last digits).

Sequence in context: A106146 A154521 A129112 * A175013 A210616 A238167

Adjacent sequences:  A239631 A239632 A239633 * A239635 A239636 A239637

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, Mar 23 2014

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 19 04:02 EDT 2019. Contains 326109 sequences. (Running on oeis4.)