|
%I #18 Dec 16 2019 09:53:10
%S 1,5,15,43,137,483,1881,7772,33292,146014,650688,2935909,13377899,
%T 61448617,284148766,1321470026,6175996065,28988110806,136575209239,
%U 645621236243,3061130340023,14552991533455,69354804657255,331251331834172,1585299655420744,7600886382041555,36504944105963117
%N Position of 5^n among the powers of primes (A000961).
%F a(n) = A065515(5^n). - _Michel Marcus_, Mar 24 2013
%o (PARI) a(n) = n=5^n; 1+sum(k=1, logint(n,2), primepi(sqrtnint(n,k))); \\ _Daniel Suteu_, Dec 15 2019
%Y Cf. A000351 (powers of 5), A000961, A065515.
%K nonn
%O 0,2
%A _Clark Kimberling_
%E a(13)-a(20) from _Robert G. Wilson v_, Dec 13 2019
%E a(21)-a(26) from _Daniel Suteu_, Dec 15 2019
|
