OFFSET
1,1
COMMENTS
Subsequence of A085751.
LINKS
Michel Lagneau, Table of n, a(n) for n = 1..999
EXAMPLE
1469 = 13*113 is in the sequence because reversal(1469) = 9641 = 31*311 where 31 = reversal(13) and 311 = reversal(113).
MAPLE
for n from 6 to 4000 do :
x:=factorset(n):n1:=nops(x):
if bigomega(n)= 2 and n1>1
then y:=convert(n, base, 10):n2:=nops(y):p:=x[1]:q:=x[2]:xp1:=convert(p, base, 10):nxp1:=nops(xp1):xq1:=convert(q, base, 10):nxq1:=nops(xq1):sp:=sum('xp1[i]*10^(nxp1-i)', 'i'=1..nxp1):sq:=sum('xq1[i]*10^(nxq1-i)', 'i'=1..nxq1):lst:={sp} union {sq}:s:=sum('y[i]*10^(n2-i)', 'i'=1..n2):x1:=factorset(s):nn1:=nops(x1):
if bigomega(s)=2 and nn1>1
then
z:=convert(s, base, 10):n3:=nops(z): p1:=x1[1]:q1:=x1[2]:
lst1:={p1} union {q1}:s1:=sum('z[i]*10^(n3-i)', 'i'=1..n3):
if lst = lst1
then
printf(`%d, `, n):
else
fi:
fi:
fi:
od:
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Michel Lagneau, May 18 2014
STATUS
approved