A105649 Smallest member of set of 4 consecutive numbers which are Smith numbers.

4463535, 6356910, 8188933, 9425550, 11148564, 15966114, 15966115, 18542654, 21673542, 22821992, 23767287, 28605144, 36615667, 39227466, 47096634, 47395362, 48072396, 54054264, 55464835, 57484614, 57756450, 57761165, 58418508, 61843387, 62577157, 64572186, 65484066

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..1000

S. S. Gupta, Smith Numbers.

Example

a(1) = 4463535 because 4463535 is the smallest member of a set of 4 consecutive numbers which are Smith numbers i.e. four consecutive numbers 4463535, 4463536, 4463537, 4463538 are all Smith numbers.

Mathematica

digSum[n_] := Plus @@ IntegerDigits[n]; smithQ[n_] := CompositeQ[n] && Plus @@ (Last @#* digSum[First@#] & /@ FactorInteger[n]) == digSum[n]; sm = smithQ /@ Range[4]; seq = {}; Do[sm = Join[Rest[sm], {smithQ[k]}]; If[And @@ sm, AppendTo[seq, k - 3]], {k, 5, 10^7}]; seq (* Amiram Eldar, Aug 18 2020 *)

Crossrefs

Cf. A006753, A050219, A059754, A105648, A105650.

Sequence in context: A019288 A237910 A244575 * A350187 A015337 A339536

Adjacent sequences: A105646 A105647 A105648 * A105650 A105651 A105652

Keyword

nonn,base

Author

Shyam Sunder Gupta, May 03 2005

Extensions

a(7) inserted and more terms added by Amiram Eldar, Aug 18 2020

Status

approved