This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A172469 #11 Apr 28 2025 16:11:50 %S A172469 7,43,101,107,149,151,157,193,199,251,257,293,307,349,401,443,449,457, %T A172469 499,557,593,599,601,607,643,701,743,751,757,857,907,1049,1051,1093, %U A172469 1151,1193,1201,1249,1301,1307,1399,1451,1493,1499,1543,1549,1601,1607 %N A172469 Primes congruent to +/-1 or +/-7 modulo 25. %C A172469 Equivalently, primes p such that the smallest extension of F_p containing the 5th roots of unity also contains the 25th roots of unity. %C A172469 In this respect, the sequence is the n=5 instance of a family of sequences. For n=3, see A129805, and for n=2, see A002144. %C A172469 Equivalently, the primes p for which, if p^t = 1 mod 5, then p^t = 1 mod 25. %F A172469 A141927 U A141932 U A141946 U A141941. [From _R. J. Mathar_, Feb 05 2010] %o A172469 (Python) %o A172469 from itertools import count, islice %o A172469 from sympy import isprime %o A172469 def A172469_gen(): # generator of terms %o A172469 yield from (7, 43) %o A172469 for n in count(50,50): %o A172469 for m in (1,7,43,49): %o A172469 if isprime(n+m): %o A172469 yield n+m %o A172469 A172469_list = list(islice(A172469_gen(),48)) # _Chai Wah Wu_, Apr 28 2025 %K A172469 easy,nonn %O A172469 1,1 %A A172469 _Katherine E. Stange_, Feb 03 2010 %E A172469 More terms from _R. J. Mathar_, Feb 05 2010