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 A152951 #22 Jun 10 2025 07:57:35
%S A152951 71,131,191,251,311,419,431,491,599,683,743,911,947,971,1031,1091,
%T A152951 1103,1151,1163,1427,1451,1511,1559,1571,1583,1607,1667,1811,1871,
%U A152951 1931,1979,2003,2111,2267,2351,2399,2411,2423,2531,2543,2591,2663,2711,2843,2927,2939
%N A152951 Complementary von Staudt prime numbers.
%C A152951 A prime number in the arithmetic progression 12n-1 which is not a von Staudt prime number, i.e., 12p <> denominator(B(p-1)/(p-1)), where B(n) is the Bernoulli number.
%H A152951 Dana Jacobsen, <a href="/A152951/b152951.txt">Table of n, a(n) for n = 0..10883</a>
%H A152951 Peter Luschny, <a href="http://www.luschny.de/math/zeta/VonStaudtPrimes.html">Von Staudt prime number, definition and computation</a>.
%p A152951 select(j->(denom(bernoulli(j-1)/(j-1))<>12*j),select(isprime,[seq(12*k-1,k=1..100)]));
%t A152951 Select[ 12*Range[200] - 1, PrimeQ[#] && 12 # != Denominator[ BernoulliB[# - 1]/(# - 1)]& ] (* _Jean-François Alcover_, Jul 29 2013 *)
%o A152951 (Perl) use ntheory ":all"; forprimes { my $p=$_; say if $_ % 12 == 11 && vecany { $_ > 3 && $_ < $p-1 && is_prime($_+1) } divisors($p-1); } 10000; # _Dana Jacobsen_, Dec 29 2015
%o A152951 (Perl) use ntheory ":all"; forprimes { say if $_ % 12 == 11 && (bernfrac($_-1))[1] != 6*$_; } 10000; # _Dana Jacobsen_, Dec 29 2015
%Y A152951 Cf. A092307.
%K A152951 easy,nonn
%O A152951 0,1
%A A152951 _Peter Luschny_, Dec 24 2008
%E A152951 More terms from _Dana Jacobsen_, Dec 29 2015