cp's OEIS Frontend

A370606 Primes p such that valuation(p-1,2) is a record.

%I A370606 #15 Feb 23 2024 20:28:49
%S A370606 2,3,5,17,97,193,257,7681,12289,40961,65537,786433,5767169,7340033,
%T A370606 23068673,104857601,167772161,469762049,2013265921,3221225473,
%U A370606 75161927681,77309411329,206158430209,2061584302081,2748779069441,6597069766657,39582418599937,79164837199873
%N A370606 Primes p such that valuation(p-1,2) is a record.
%H A370606 Chai Wah Wu, <a href="/A370606/b370606.txt">Table of n, a(n) for n = 1..1770</a>
%o A370606 (PARI) r=-1;forprime(p=2,10^12,v=valuation(p-1,2);if(v>r,print1(p,", ");r=v))
%o A370606 (Python)
%o A370606 from itertools import count, islice
%o A370606 from sympy import isprime
%o A370606 def A370606_gen(): # generator of terms
%o A370606     a = 1
%o A370606     while True:
%o A370606         for q in count(a,a):
%o A370606             if isprime(q+1):
%o A370606                 yield q+1
%o A370606                 a = (q&-q)<<1
%o A370606                 break
%o A370606 A370606_list = list(islice(A370606_gen(),30)) # _Chai Wah Wu_, Feb 23 2024
%Y A370606 Cf. A084924 (valuation(p+1,2) is a record).
%Y A370606 Cf. A370607 (corresponding 2-valuations).
%K A370606 nonn
%O A370606 1,1
%A A370606 _Joerg Arndt_, Feb 23 2024
%E A370606 a(21)-a(28) from _Chai Wah Wu_, Feb 23 2024