A098840 Smith triangular numbers.

378, 666, 861, 2556, 5253, 7503, 10296, 16653, 27261, 28920, 29890, 32896, 46056, 72771, 84255, 85905, 92235, 94395, 120786, 132870, 141778, 157641, 215496, 328455, 345696, 385881, 386760, 396495, 424581, 529935, 533028, 588070, 654940

Offset: 1

Author

Shyam Sunder Gupta, Oct 10 2004

Keywords

• base
• nonn

Examples

			a(1) = 378 because 378 is a Smith number as well as a triangular number.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Harvey P. Dale)
• Shyam Sunder Gupta, Triangular Numbers, Exploring the Beauty of Fascinating Numbers, Springer (2025) Ch. 3, 83-125. See also Smith Numbers, Ch. 4, 127-157.

Crossrefs

Intersection of A000217 and A006753.

Programs

Mathematica

Rest[Select[Accumulate[Range[1500]],!PrimeQ[#]&&Total[IntegerDigits[#]] == Total[Flatten[ IntegerDigits/@Flatten[Table[#[[1]],{#[[2]]}]&/@ FactorInteger[ #]]]]&]] (* Harvey P. Dale, Oct 20 2012 *)