OFFSET
2,1
EXAMPLE
a(6) = 100006 = 2*13*1613 and 600001 = 19*23*1373 both have prime signature p*q*r, p,q,r are primes.
PROG
(PARI) rev(n) = fromdigits(Vecrev(digits(n)));
psig(n) = vecsort(factor(n)[, 2]~);
a(n) = {my(k = 10^n+1); while(k == rev(k) || psig(k) != psig(rev(k)), k++); k; } \\ Amiram Eldar, May 19 2024
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Sep 02 2003
EXTENSIONS
More terms from David Wasserman, Apr 19 2005
More terms from Amiram Eldar, May 19 2024
STATUS
approved