A105329 - OEIS

%I #24 Aug 31 2024 22:02:06

%S 1,2,6,7,12,14,181,1053,1057,2614,40089,40114,40117,40119,100346,

%T 100352,100358,251707,251742,251743,251754,251757,1617173,4124458,

%U 10553513,27067262,27067272,179992922,179992932,179993012,179993172,3140421806,3140421838,3140421866,3140421872,55762149076,145935689366

%N Numbers k such that prime(k+1) == 5 (mod k).

%C There are no further terms up to 215000000. - _Farideh Firoozbakht_, May 13 2005

%C Integers k such that A004649(k+1) = 5. - _Michel Marcus_, Dec 30 2022

%t Do[If[5 == Mod[Prime[n + 1], n], bb = Append[bb, n]], {n, 1, 251758}];

%t bb={};Do[If[5 == Mod[Prime[n + 1], n], bb = Append[bb, n]], {n, 1, 251758}];bb  (* _Farideh Firoozbakht_, May 13 2005 *)

%o (Sage)

%o def A105329(max) :

%o     terms = []

%o     p = 3

%o     for n in range(1, max+1) :

%o         if (p - 5) % n == 0 : terms.append(n)

%o         p = next_prime(p)

%o     return terms

%o # _Eric M. Schmidt_, Feb 05 2013

%Y Cf. A004649, A105286, A105287, A105288, A105290, A105451.

%K nonn

%O 1,2

%A _Zak Seidov_, Apr 30 2005

%E More terms from _Farideh Firoozbakht_, May 13 2005

%E First two terms inserted by _Eric M. Schmidt_, Feb 05 2013

%E a(28)-a(29) corrected, a(30)-a(37) added by _Max Alekseyev_, Aug 31 2024