A309003 Carmichael numbers divisible by the sum of their prime factors, sopfr (A001414).

3240392401, 13577445505, 14446721521, 84127131361, 203340265921, 241420757761, 334797586201, 381334973041, 461912170321, 1838314142785, 3636869821201, 10285271821441, 17624045440981, 18773053896961, 20137015596061, 24811804945201, 26863480687681, 35598629998801

Offset

1,1

Comments

Intersection of A002997 and A308643.

Intersection of A002997 and A036844.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (calculated using data from Claude Goutier)

Claude Goutier, Compressed text file carm10e22.gz containing all the Carmichael numbers up to 10^22.

Index entries for sequences related to Carmichael numbers.

Example

3240392401 = 29*37*41*73*1009, A001414(3240392401)=1189 = 29*41.

Prog

(PARI) sopfr(f) = f[, 1]~*f[, 2];
isCarmichael(n, f)= bittest(n, 0) && !for(i=1, #f~, (f[i, 2]==1 && n%(f[i, 1]-1)==1)||return) && (#f~>1);
isok(n) = my(f=factor(n)); isCarmichael(n, f) && !(n % sopfr(f)); \\ Michel Marcus, Jul 07 2019

Crossrefs

Cf. A002997, A001414, A036844, A046347, A308643.

Sequence in context: A198298 A074773 A340133 * A348811 A251523 A155961

Adjacent sequences: A309000 A309001 A309002 * A309004 A309005 A309006

Keyword

nonn

Author

David James Sycamore, Jul 05 2019

Status

approved