Trigonal Cipher
The Trigonal cipher maps each letter to its triangular number: A=1, B=3, C=6, through Z=351 (the 26th triangular number).
Letter values
a
1
b
3
c
6
d
10
e
15
f
21
g
28
h
36
i
45
j
55
k
66
l
78
m
91
n
105
o
120
p
136
q
153
r
171
s
190
t
210
u
231
v
253
w
276
x
300
y
325
z
351