OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
a(2)=377 is a term because 377 is a semiprime and all digits are equal to 7 except one.
MATHEMATICA
Rest[Flatten[Table[Select[FromDigits/@Flatten[Permutations/@Table[ PadRight[ {n}, k, 7], {n, 0, 9}], 1], PrimeOmega[#]==2&], {k, 3, 7}]]]//Union (* Harvey P. Dale, Jul 25 2020 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Shyam Sunder Gupta, Apr 29 2005
STATUS
approved