permutation and combination, binomial theorem puzzle

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123456789101112131415161718
Across
  1. 6. pascal triangle
  2. 9. remainder when 6^n-5n is divided by 25
  3. 11. numbers greater than 10k formed by 1,2,0,2,4,2,4
  4. 14. number of words formed by BEAUTY
  5. 15. number of words formed from letters of MINIMUM
  6. 16. no. of words formed with MISSISSIPPI s.t. all I's togethr
  7. 17. 6-digit no. div by 10 made from 0,1,3,5,7,9 without rep
  8. 18. number of terms in (1+x)^14
Down
  1. 1. selection+ arrangement
  2. 2. selection
  3. 3. C(2n,3):C(n,3)=12:1
  4. 4. number of ways of inviting one or more friends out of 5
  5. 5. arrangement
  6. 7. P(n-1,3):P(n,4)=1/9
  7. 8. C(8,3)+C(8,2)
  8. 10. number of 4-letters words from SINGAPORE
  9. 12. C(18,4)
  10. 13. 8!
  11. 17. number of terms in (1-2x+x^2)^7