A284261 a(n) = A284258(n) - A284258(A003961(n)).

0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1

Offset: 1

Author

Antti Karttunen, Mar 24 2017

Keywords

• nonn

Comments

The first 2 occurs at n = 429 = 3*11*13. A003961(429) = 1105 = 5*13*17.

The first 3 occurs at n = 7293 = 3*11*13*17. A003961(7293) = 20995 = 5*13*17*19.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10001

Crossrefs

Cf. A001221, A003961, A284254, A284258, A252459.

Programs

Mathematica

Table[If[n == 1, 0, Subtract @@ Map[Count[#, d_ /; d > First[#]^2] &@ FactorInteger[#][[All, 1]] &, {n, Times @@ Map[#1^#2 & @@ # &, FactorInteger[n] /. {p_, e_} /; e > 0 :> {Prime[PrimePi@ p + 1], e}] - Boole[n == 1]}]], {n, 120}] (* Michael De Vlieger, Mar 24 2017 *)

Scheme

(define (A284261 n) (- (A284258 n) (A284258 (A003961 n))))

Formula

a(n) = A284258(n) - A284258(A003961(n)).

a(n) = A001221(A284254(n)) - A001221(A284254(A003961(n))).

Extensions

Secondary offset corrected by Antti Karttunen, Dec 15 2017