27 = 1+9+6+8+3 and 273 = 19683
27 = 32 + 32 + 32 = 52 + 12 + 12.
27 = 12 − 3 − 45 − 6 + 78 − 9
27 = 9 − 87 + 65 + 43 − 2 − 1
27 = 0^4 − 1^9 + 2^8 + 3^5 − 4^7 + 5^6 + 6^3 + 7^1 + 8^2 + 9^0
7 = (1 + 1 + 1)(1+1+1)
= 22 + 2 + 2 + 2/2
= 33
= 4 × 4 + 44/4 = 4!+ √4 + (4 ÷ 4)
= 5 × 5 + (5 + 5)/5
= 6 × 66/(6 + 6) − 6
= 77 − 7 × 7 − 7/7
= 8 + 8 + 88/8
= 9 + 9 + 9
a(n) = 3*n*(n + 3)/2. (n = 3)
Numbers k such that (35*10^k - 11)/3 is prime
Number of edges in an equilateral triangle when n internal equilateral triangles are drawn between the 3n points that divide each side into n+1 equal parts. (n=2)
Number of ways to partition 2n+1 into distinct positive integers, n = 7
Factors: 1, 3, 9, 27
Representations, Binary to Hexadecimal:
11011_2
1000_3
123_4
102_5
43_6
36_7
33_8
30_9
25_11
23_12
21_13
1d_14
1c_15
1b_16
Undergraduate Texts in Mathematics
Graduate Studies in Mathematics
