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A172240 as a simple table

na(n)
13
27
313
417
519
629
731
837
941
1043
1153
1261
1367
1471
1573
1679
1783
1889
1997
20101
21103
22109
23113
24127
25131
26137
27139
28149
29151
30157
31163
32173
33181
34191
35193
36197
37199
38211
39223
40229
41233
42239
43241
44251
45257
46263
47269
48271

[3,7,13,17,19,29,31,37,41,43,53,61,67,71,73,79,83,
 89,97,101,103,109,113,127,131,137,139,149,151,157,
 163,173,181,191,193,197,199,211,223,229,233,239,
 241,251,257,263,269,271]