A318889 a(n) = A001065(n) - A001065(A252463(n)).

0, 1, 0, 2, 0, 5, 0, 4, 1, 7, 0, 10, 0, 9, 3, 8, 0, 17, 0, 14, 3, 13, 0, 20, 2, 15, 6, 18, 0, 33, 0, 16, 5, 19, 4, 34, 0, 21, 3, 28, 0, 43, 0, 26, 17, 25, 0, 40, 2, 37, 5, 30, 0, 53, 6, 36, 3, 31, 0, 66, 0, 33, 19, 32, 4, 63, 0, 38, 5, 61, 0, 68, 0, 39, 28, 42, 6, 73, 0, 56, 25, 43, 0, 86, 6, 45, 7, 52, 0, 111, 4, 50, 3, 49, 4, 80, 0

Offset

1,4

Links

Antti Karttunen, Table of n, a(n) for n = 1..16384

Formula

a(n) = A001065(n) - A319699(n) = A001065(n) - A001065(A252463(n)).

Prog

(PARI)
A001065(n) = (sigma(n)-n);
A064989(n) = {my(f); f = factor(n); if((n>1 && f[1, 1]==2), f[1, 2] = 0); for (i=1, #f~, f[i, 1] = precprime(f[i, 1]-1)); factorback(f)};
A252463(n) = if(!(n%2), n/2, A064989(n));
A318889(n) = (A001065(n) - A001065(A252463(n)));

Crossrefs

Cf. A001065, A252463.

Cf. also A319699, A319700, A319703, A319989, A320107, A320111.

Sequence in context: A019962 A086131 A355875 * A319853 A228620 A369743

Adjacent sequences: A318886 A318887 A318888 * A318890 A318891 A318892

Keyword

nonn

Author

Antti Karttunen, Nov 22 2018

Status

approved