A352462 Numbers k with the property that k ends in the sum of the digits of k.

1, 2, 3, 4, 5, 6, 7, 8, 9, 910, 911, 912, 913, 914, 915, 916, 917, 918, 919, 1810, 1811, 1812, 1813, 1814, 1815, 1816, 1817, 1818, 1819, 2710, 2711, 2712, 2713, 2714, 2715, 2716, 2717, 2718, 2719, 3610, 3611, 3612, 3613, 3614, 3615, 3616, 3617, 3618, 3619, 4510, 4511, 4512, 4513, 4514, 4515, 4516

Offset: 1

Author

Eric Angelini and Carole Dubois, Mar 17 2022

Keywords

• base
• nonn

Examples

			a(10) = 910, which ends in 10 = 9 + 1 + 0.
a(20) = 1810, which ends in 10 = 1 + 8 + 1 + 0.
a(39) = 2719, which ends in 19 = 2 + 7 + 1 + 9.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A052018, A352461.

Programs

Mathematica

q[n_] := Module[{d = IntegerDigits[n], s, ds, nds}, s = Plus @@ d; s = IntegerDigits[s]; nds = Length[ds]; ds == d[[-nds ;; -1]]]; Select[Range[4516], q] (* Amiram Eldar, Mar 17 2022 *)
Select[Range[4516],StringEndsQ[ToString[#],ToString[Plus@@IntegerDigits[#]]]&] (* Ivan N. Ianakiev, Mar 18 2022 *)
sdkQ[n_]:=Module[{idn=IntegerDigits[n],d},d=IntegerDigits[Total[idn]];d==Take[idn,-Length[d]]]; Select[Range[5000],sdkQ] (* Harvey P. Dale, Apr 19 2022 *)

Python

def ok(n): s = str(n); return s.endswith(str(sum(map(int, s))))
print([k for k in range(1, 4517) if ok(k)]) # Michael S. Branicky, Mar 17 2022