Counting

1. Unity
2. The even prime
3. The only consecutive prime
4. First perfect square
5. The first elder twin prime
6. First squarefree composite
7. Perfect number in Babylonian numerology
8. First perfect cube
9. First non-unity Kaprekar number
10. Base.
11. Landed on the moon.
12. First sublime number.
13. Months in a lunar year.
14. Fortnight
15. Quarter of an hour.
16. Lowest perfect forth.
17. "The most random number"
18. Chapters in Ulysses
19. The impossible cribbage score
20. First primitive abundant number
21. Spots on a standard die
22. Paths in the tree of life
23. Read the Illuminatus Trilogy an you'll see where the whole fuss started.
24. Squares in a tesseract
25. First aspiring number
26. Number of cards of a given color in a deck of cards.
27. Plastic parts in a Rubik's cube
28. Only natural number with a unique Kayles nim-value.
29. First number that is a  Pell prime and a Pillai prime
30. First sphenic number.
31. Number of triads in the standard twelve tone musical system
32. First perfect fifth
33. Bones in typical human spine
34. The first semiprime Markov number
35. Youngest age at which one can legally become president of the USA.
36. Number of Tzadikim Nistarim
37. First irregular prime
38. Number of minutes a Stargate can stay open if not fed by an external power source.
39. First perfect totient semiprime Perrin number
40. First pentagonal pyramidal semiperfect octagonal Størmer number
41. First centered-square (natural Einstein Proth) cousin prime
42. The Answer