49 = 1 × 2 + 3 × 4 + 5 + 6 + 7 + 8 + 9
49 = 9 + 8 + 7 + 6 + 5 + 4 × 3 + 2 × 1
49 = 0^4 − 1^8 − 2^6 − 3^9 + 4^7 + 5^5 + 6^3 + 7^1 + 8^2 + 9^0
49 = 2^2 + 3^2 + 6^2
49 , smallest number with exactly 8 representations as a sum of 3 distinct primes: 49 = 3 + 5 + 41 = 3 + 17 + 29 = 5 + 7 + 37 = 5 + 13 + 31 = 7 + 11 + 31 = 7 + 13 + 29 = 7 + 19 + 23 = 13 + 17 + 19
100^49 + 49 is a Prime Number
Wolstenholme number
a(n) = n*(7*n + 11)/2 + 1.
Number of points of norm <= 4^2 in square lattice.
Number k such that 9^k + 2 is prime.
Number of prime knots with 9 crossings.
Number of intersections of diagonals in the interior of a regular 8-gon.
Smallest number whose sum of digits is 13.
Factors: 1, 7, 49
Forty-nine
Representations, Binary to Hexadecimal:
110001_2
1211_3
301_4
144_5
121_6
100_7
61_8
54_9
45_11
41_12
3a_13
37_14
34_15
31_16
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Undergraduate Texts in Mathematics
Graduate Studies in Mathematics
