OFFSET
1,1
COMMENTS
The home primes of 49 and 77 are not currently known. Other terms in this sequence include 101, 131, 151, 159, 181, 191, 219, 313, 373, 383, 532, 679, 727, 757, 787, 797, 919, 929,...
The non-palindromic numbers (or composite numbers) are 38, 39, 159, 219, 532, 679, ...
LINKS
P. de Geest, Repeated factorization of concatenated..., world of numbers.
Robert Israel, Terms with A037274(n) < 10^11. All these numbers are in the sequence, but there may be others.
Mersenne Wiki, Base 10 Home Prime Results
Eric Weisstein, Home prime
EXAMPLE
Home prime of 38 is 373.
Home prime of 39 is 313.
Home prime of 159 is 353.
Home prime of 219 is 373.
Home prime of 532 is 37573.
Home prime of 679 is 797.
MAPLE
filter:= proc(n)
local F, k, q;
F:= sort(map(t -> t[1]$t[2], ifactors(n)[2]));
F:= map(t -> op(ListTools:-Reverse(convert(t, base, 10))), F);
q:= add(F[-k]*10^(k-1), k=1..nops(F));
if isprime(q) then evalb(F = ListTools:-Reverse(F)) else procname(q) fi
end proc:
map(filter, [$2..48]); # Robert Israel, Jul 11 2016
CROSSREFS
KEYWORD
base,nonn,more
AUTHOR
Kausthub Gudipati, Sep 16 2011
EXTENSIONS
Name corrected by Robert Israel, Jul 11 2016
STATUS
approved