Truncatable (left and right side; any number of truncated digits allowed) decimal primes,whose sum of digits is square
franktaw at netscape.net
franktaw at netscape.net
Thu Dec 27 00:43:15 CET 2007
This strikes me as a good example of the kind of sequence that should
not be added to the OEIS, unless there is some non-obvious reason why
it is of interest.
Franklin T. Adams-Watters
-----Original Message-----
From: Alexander Povolotsky <apovolot at gmail.com>
Here are the three terms of the potential sequence of truncatable
(left and right side; any number of truncated digits allowed) decimal
primes, whose sum of digits (in decimal form) is square:
5375937799, 3953759377999393, 9539537593779993937
a(1)=5375937799 because it arises from truncating a(2) and
5 + 3 + 7 + 5 + 9 + 3 + 7 + 7 + 9 + 9 = 64
a(2)=3953759377999393 because it arises from truncating a(3) and
3 + 9 + 5 + 3 + 7 + 5 + 9 + 3 + 7 + 7 + 9 + 9 + 9 + 3 + 9 + 3 = 100
a(3)=9539537593779993937 because
9 + 5 + 3 + 9 + 5 + 3 + 7 + 5 + 9 + 3 + 7 + 7 + 9 + 9 + 9 + 3 + 9 + 3 +
7 = 121
Is this sequence finite (hope not) ?
Are there similar sequences ?
________________________________________________________________________
More new features than ever. Check out the new AIM(R) Mail ! -
http://webmail.aim.com
More information about the SeqFan
mailing list