A328240 Numbers k such that the second arithmetic derivative of A276086(k) is prime.

4, 12, 32, 35, 40, 46, 47, 65, 67, 68, 71, 73, 74, 76, 220, 221, 225, 226, 227, 250, 256, 257, 276, 283, 284, 420, 421, 425, 426, 436, 486, 489, 494, 2324, 2325, 2352, 2370, 2387, 2525, 2530, 2531, 2555, 2560, 2565, 2566, 2583, 2596, 2734, 2739, 2760, 2765, 2769, 2771, 2773, 2795, 2797, 2798, 2803, 4623, 4627, 4628

Offset

1,1

Comments

Numbers k for which A003415(A327860(k)) = A003415(A003415(A276086(k))) is a prime.

Numbers k such that A276086(k) is in A192192, or equally, k such that A327860(k) is in A157037.

Links

Antti Karttunen, Table of n, a(n) for n = 1..1217

Index entries for sequences related to primorial base

Formula

For all n, a(A327969(n)) <= 5.

Prog

(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A327860(n) = { my(m=1, i=0, s=0, pr=1, nextpr); while((n>0), i=i+1; nextpr = prime(i)*pr; if((n%nextpr), my(e=((n%nextpr)/pr)); m *= (prime(i)^e); s += (e / prime(i)); n-=(n%nextpr)); pr=nextpr); (s*m); };
isA328240(n) = isprime(A003415(A327860(n)));

Crossrefs

Cf. A003415, A157037, A192192, A276086, A327860, A327969, A328233.

Subsequence of A328116 and of A328242.

Sequence in context: A171844 A324971 A273387 * A369817 A161217 A152527

Adjacent sequences: A328237 A328238 A328239 * A328241 A328242 A328243

Keyword

nonn

Author

Antti Karttunen, Oct 10 2019

Status

approved