A324290 a(n) = 1 if for every prime divisor p of n, p-1 divides n-1, 0 otherwise; characteristic function of A087441.

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

Offset

1

Comments

Function c1(n) = A008966(n)*a(n) is the characteristic function of A324050.

Function c2(n) = A008966(n)*a(n) - A080339(n) is the characteristic function of Carmichael numbers, A002997.

Function c3(n) = a(n) - A010055(n) is the characteristic function of A087442.

Links

Antti Karttunen, Table of n, a(n) for n = 1..101101

Index entries for characteristic functions

Formula

a(n) >= A010055(n) >= A010051(n) for all n.

Prog

(PARI) A324290(n) = if(1==n, 1, my(f=factor(n)); for(i=1, #f[, 1], if((n-1)%(f[i, 1]-1), return(0))); (1));

Crossrefs

Cf. A002997, A008966, A010051, A010055, A080339, A087441, A087442, A324050, A324053.

Sequence in context: A011750 A340375 A010055 * A325964 A344885 A345064

Adjacent sequences: A324287 A324288 A324289 * A324291 A324292 A324293

Keyword

nonn

Author

Antti Karttunen, Feb 22 2019

Status

approved