seq: Sum of base 26 values of the English name of n

[Jonathan Post]

So Franklin T. Adams-Watters recommends submitting:

Sum of letter values (a=1, b=2, ..., z=26) of the English name of n,
excluding spaces and hyphens.

n   a(n) comment
0   64    LetterValue(z)+ LetterValue(e)+ LetterValue(r)+
LetterValue(o) = 26+5+18+15 = 64
1   34    o+n+e = 15+14+5 = 34
2   58    t+w+o = 20+23+15
3   56
4   60
5   42
6   52
7   65
8   49
9   42    same value as a(5)
10  39   t+e+n = 20+5+14
11  63
12  87
13  99   note that "teen" --> 44, so a(Xteen)=a(X)+44
14  104
15  65   same value as a(7)
16  96
17  109
18  93
19  66
20  107  t+w+e+n+t+y = 20+23+5+14+20+25, so a(twentyX)=107+a(X)
21  141
22  165
23  163
24  167
25  149
26  159
27  172
28  156
29  149  same value as a(25)
30  100  t+h+i+r+t+y = 20+8+9+18+20+25, so a(thirtyX)=100+a(X)
31  134
32  158
33  156
34  160
35  142
36  152
37  165
38  149  same vale as a(25)=a(29)
39  142  same value as a(35)
40  84   f+o+r+t+y, so a(fortyX) = 84 + a(x)

Would anyone like to correct, code, extend, answer the questions about
fixed points, trajectories on iteration, the disjoint classes of
possible and impossible values, or the equivalent in another language
with or without a different alphabet?