login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A068842 Smallest prime larger than 2^n whose digits begin with those of 2^n. 1
11, 23, 41, 83, 163, 3203, 641, 1283, 25601, 51203, 10243, 20483, 40961, 81929, 163841, 327689, 6553621, 1310723, 2621447, 5242883, 10485767, 20971529, 41943049, 838860817, 167772161, 335544323, 6710886407, 1342177283 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..27.

EXAMPLE

a(5) = 3203 with leading digits 32 = 2^5.

MATHEMATICA

f[n_] := For[x=10, True, x*=10, For[y=0, y<x, y++, If[PrimeQ[x*n+y], Return[x*n+y]]]]; a[n_] := f[2^n]

CROSSREFS

Cf. A068841.

Sequence in context: A052034 A077041 A190797 * A199848 A228444 A191235

Adjacent sequences:  A068839 A068840 A068841 * A068843 A068844 A068845

KEYWORD

nonn,base

AUTHOR

Amarnath Murthy, Mar 10 2002

EXTENSIONS

Edited by Dean Hickerson, Jun 09 2002

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 3 07:58 EDT 2021. Contains 346435 sequences. (Running on oeis4.)