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
Keywords
Examples
3240392401 = 29*37*41*73*1009, A001414(3240392401)=1189 = 29*41.
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.
Programs
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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
Comments