|
|
|
|
1, 1, 5, 1, 3, 11, 1, 1, 17, 19, 7, 23, 25, 9, 29, 1, 11, 35, 37, 13, 41, 43, 15, 47, 49, 17, 53, 55, 19, 59, 61, 1, 65, 67, 23, 71, 73, 25, 77, 79, 27, 83, 85, 29, 89, 7, 31, 95, 97, 11, 101, 103, 35, 107, 109, 37, 113, 115, 3, 17, 11, 41, 125, 1, 43, 131, 19, 45, 137, 139, 47, 143, 145, 49, 149, 151, 51, 155
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
LINKS
|
|
|
FORMULA
|
a(n) = (2*n-1) / gcd(2*n-1, A324054(n-1)).
|
|
PROG
|
(PARI)
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t };
A156552(n) = {my(f = factor(n), p, p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res}; \\ From A156552
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|