A103124 1/5-Smith numbers.
399996663, 666609999, 669969663, 690696969, 699966663, 2789929969, 3066999963, 3366339999, 3366999933, 3399696663, 3399996633, 3666699663, 3669933993, 3933969693, 6066690999, 6069996663, 6099996633, 6393996933, 6399636963, 6666009999, 6669669633, 6966939633
Offset: 1
Examples
399996663 is a 5^(-1) Smith number because the digit sum of 399996663, i.e., S(399996663) = 3 + 9 + 9 + 9 + 9 + 6 + 6 + 6 + 3 = 60, which is equal to 5 times the sum of the digits of its prime factors, i.e., 5*Sp(399996663) = 5*Sp(3*11*101*120011) = 5*(3 + 1 + 1 + 1 + 0 + 1 + 1 + 2 + 0 + 0 + 1 + 1) = 60.
Links
- Shyam Sunder Gupta, Smith Numbers.
- Shyam Sunder Gupta, Smith Numbers, Exploring the Beauty of Fascinating Numbers, Springer (2025) Ch. 4, 127-157.
- Wayne L. McDaniel, The Existence of infinitely Many k-Smith numbers, Fibonacci Quarterly, 25(1987), pp. 76-80.
Crossrefs
Cf. A006753.
Extensions
a(6)-a(22) from Donovan Johnson, Sep 20 2011