A395053 a(n) = 1 if the greatest prime dividing A276085(n) is larger than the greatest prime dividing n, otherwise 0, where A276085 is fully additive with a(p) = p#/p. a(1) = 0 by convention.

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

Offset

1

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for characteristic functions.

Formula

a(n) = [n>1 and A395052(n) > A006530(n)], where [ ] is the Iverson bracket.

Prog

(PARI)
A276085(n) = { my(f=factor(n)); sum(k=1, #f~, f[k, 2]*prod(i=1, primepi(f[k, 1]-1), prime(i))); };
A395053(n) = if(n<=1 || isprime(n), 0, my(f = factor(n), gpf = vecmax(f[, 1]), x = A276085(n)); forprime(p=2, gpf, x /= (p^valuation(x, p))); (x>1));

Crossrefs

Characteristic function of A395054.

Cf. A006530, A276085, A395052, A395055.

Cf. also A395043.

Sequence in context: A011693 A144198 A144200 * A011695 A011706 A011697

Adjacent sequences: A395049 A395051 A395052 * A395054 A395055 A395057

Keyword

nonn,easy

Author

Antti Karttunen, Apr 15 2026

Status

approved