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A062948
a(n) = H(A002808(n)) where H(n) is the half-totient function, H(n) = phi(n)/2: (A023022) and A002808(n) are the composites.
1
1, 1, 2, 3, 2, 2, 3, 4, 4, 3, 4, 6, 5, 4, 10, 6, 9, 6, 4, 8, 10, 8, 12, 6, 9, 12, 8, 6, 10, 12, 11, 8, 21, 10, 16, 12, 9, 20, 12, 18, 14, 8, 15, 18, 16, 24, 10, 16, 22, 12, 12, 18, 20, 18, 30, 12, 16, 27, 20, 12, 32, 21, 28, 20, 12, 36, 22, 30, 23, 36, 16, 21, 30, 20, 16, 24, 24, 26
OFFSET
1,3
LINKS
PROG
(PARI) H(n)=eulerphi(n)/2;
j=[]; for(n=2, 200, if(isprime(n), n+1, j=concat(j, H(n) ))); j
(PARI) { n=0; for (m=2, 10^9, if (!isprime(m), write("b062948.txt", n++, " ", eulerphi(m)/2); if (n==1000, break)) ) } \\ Harry J. Smith, Aug 14 2009
CROSSREFS
Sequence in context: A303539 A303540 A137266 * A365159 A358639 A358640
KEYWORD
easy,nonn
AUTHOR
Jason Earls, Jul 21 2001
EXTENSIONS
Offset changed from 2 to 1 by Harry J. Smith, Aug 14 2009
STATUS
approved