

A181837


T(n,k) = [k is strongly prime to n], the indicator function of strong coprimality, triangle read by rows.


1



0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0
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OFFSET

0


COMMENTS

k is strongly prime to n iff k is relatively prime to n and k does not divide n1.
T(n,k) = [k is strong prime to n] where [] denotes the Iverson bracket.


LINKS

Table of n, a(n) for n=0..81.
Peter Luschny, Strong coprimality.


EXAMPLE

[n=0] 0
[n=1] 0, 1
[n=2] 0, 0, 0
[n=3] 0, 0, 0, 0
[n=4] 0, 0, 0, 0, 0
[n=5] 0, 0, 0, 1, 0, 0
Let n = 5 then the numbers prime to n are {1, 2, 3, 4} and the positive divisors of n1 are {1, 2, 4}. Thus only 3 is strong prime to 5.


MAPLE

A181837_triangle := proc(M) local strongCoprimes, triangle;
strongCoprimes := n > select(k>igcd(k, n)=1, {$1..n})
minus numtheory[divisors](n1):
triangle := proc(N, C) local T, L, k, n;
for n from 0 to N do
T := C(n); L := NULL;
for k from 0 to n do
L := L, `if`(member(k, T), 1, 0)
od;
print(L)
od end:
triangle(M, strongCoprimes) end:


CROSSREFS

Cf. A181830, A181831, A181832, A181838, A054431.
Sequence in context: A191153 A214210 A204547 * A185706 A188371 A188472
Adjacent sequences: A181834 A181835 A181836 * A181838 A181839 A181840


KEYWORD

nonn,tabl


AUTHOR

Peter Luschny, Nov 17 2010


STATUS

approved



