1,3
These and subsequent values for (twice) squarefree and (twice) prime-squared orders can be found in the Liskovets reference.
V. A. Liskovets, Some identities for enumerators of circulant graphs.
Sequence in context: A096981 A035541 A187502 * A172993 A135279 A035631
Adjacent sequences: A060963 A060964 A060965 * A060967 A060968 A060969
nonn
Valery A. Liskovets (liskov(AT)im.bas-net.by), May 09 2001