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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A109181 Primes q such that q is the sum of the squared decimal digits of a prime number p. 3
2, 13, 17, 37, 73, 2, 11, 11, 59, 59, 131, 83, 131, 163, 17, 89, 11, 19, 59, 19, 67, 43, 67, 139, 139, 17, 97, 41, 113, 53, 61, 101, 37, 53, 61, 101, 73, 109, 131, 67, 139, 107, 179, 149, 109, 137, 83, 163, 139, 131, 179, 163, 211, 11, 83, 11, 19, 83, 131, 11, 83, 47, 67, 103, 11, 19, 59, 47, 107, 43, 67, 107, 179, 47, 127, 167, 199, 131, 67, 163 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

For the primes p see A052034.

EXAMPLE

q=13 is OK because 13=2^2+3^2 and merging digits 2 and 3 makes p=23 which is a prime.

MAPLE

a:=proc(n) local nn, L: nn:=convert(n, base, 10): L:=nops(nn): if isprime(n) = true and isprime(add(nn[j]^2, j=1..L))=true then add(nn[j]^2, j=1..L) else end if end proc: seq(a(n), n=1..1200); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 08 2008

CROSSREFS

Cf. A052034.

Sequence in context: A177964 A174050 A122487 * A175448 A067522 A128852

Adjacent sequences:  A109178 A109179 A109180 * A109182 A109183 A109184

KEYWORD

base,nonn

AUTHOR

Zak Seidov (zakseidov(AT)yahoo.com), Jun 21 2005

EXTENSIONS

More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu) and Alvin H. Belt (AlvinBelt(AT)msn.com), Jan 08 2008

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 10:53 EST 2012. Contains 205904 sequences.