OFFSET
1,1
COMMENTS
Proper subset of A255966. - Michel Marcus , Mar 13, 2015.
EXAMPLE
10878 is in this sequence since it is the 147th triangular number and 1 = 8-7, 0 = 8-8, 8 = 8-0, 7 = 8-1 and 8 = 8-0, where the eights are different digits.
MATHEMATICA
fQ[n_] := Block[{id = IntegerDigits@ n, lng = 1 + Floor@ Log10@ n}, Union@ Table[c = Complement[ Range@ lng, {i}]; MemberQ[ Union@ Flatten@ Table[Abs[id[[j]] - id[[k]]], {j, c}, {k, c}], id[[i]]], {i, lng}] == {True}]; tri[n_] := n(n + 1)/2; Select[ tri@ Range@ 1050, fQ]
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Michel Lagneau and Robert G. Wilson v, Mar 11 2015
STATUS
approved