|
%I #14 Sep 29 2013 05:25:32
%S 9,27,49,63,77,81,91,99,117,119,121,133,143,153,161,169,171,187,189,
%T 203,207,209,217,221,243,247,253,259,261,279,287,289,297,299,301,319,
%U 323,329,333,341,343,351,361,369,371,377,387,391,403,407,413,423,427,437
%N Nonprime numbers k such that binomial(k+p,k) mod k = 1, where p=6.
%C Also composite n such that binomial(7*n,7)== n (mod n^2). - _Gary Detlefs_, Sep 24 2013
%o (PARI) isok(n) = ! isprime(n) && ((binomial(n+6, n) % n) == 1); \\ _Michel Marcus_, Sep 25 2013
%o (PARI) isok(n) = ! isprime(n) && ((binomial(7*n, 7) % n^2) == n); \\ _Michel Marcus_, Sep 25 2013
%Y Cf. A000040, A133620-A133625, A133630, A038509, A133634-A133636.
%Y Cf. A133876, A133886, A133880, A133890, A133900, A133910.
%K nonn
%O 1,1
%A _Hieronymus Fischer_, Sep 30 2007
|
