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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A199169 Primes such that the sum of the squares of their digits equals the number of their digits. 0
11, 102001, 1000121, 1000211, 1002101, 1010201, 1020011, 1020101, 1021001, 1102001, 1120001, 1201001, 2001101, 2100011, 2110001, 100012111, 100101121, 100110121, 100112101, 100121011, 100211101, 101020111, 101100211, 101102101, 101110201, 101210101, 102100111 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A subsequence of 1, 11, 111, 1111, 2000, 10002, 10020, 10200, 11111,... which contains n such that A003132(n) = A055642(n). - R. J. Mathar, Nov 07 2011

LINKS

Table of n, a(n) for n=1..27.

EXAMPLE

a(2) = 102001 is in the sequence because 1^2+0^2+2^2+0^2+0^2+1^2 = 6 = length(a(2)).

MATHEMATICA

fQ[n_] := Plus @@ (IntegerDigits[n]^2) == IntegerLength[n]; Select[Prime[Range[100000000]], fQ] (* Robert G. Wilson v, Nov 07 2011 *)

CROSSREFS

Cf. A069710.

Sequence in context: A165934 A110780 A087395 * A145571 A049193 A216596

Adjacent sequences:  A199166 A199167 A199168 * A199170 A199171 A199172

KEYWORD

nonn,base

AUTHOR

Michel Lagneau, Nov 03 2011

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 January 22 10:52 EST 2020. Contains 331144 sequences. (Running on oeis4.)