A083678 Numbers m = d_1 d_2 ... d_k (in base 10) with properties that k is even and d_i + d_{k+1-i} = 10 for all i.

19, 28, 37, 46, 55, 64, 73, 82, 91, 1199, 1289, 1379, 1469, 1559, 1649, 1739, 1829, 1919, 2198, 2288, 2378, 2468, 2558, 2648, 2738, 2828, 2918, 3197, 3287, 3377, 3467, 3557, 3647, 3737, 3827, 3917, 4196, 4286, 4376, 4466, 4556, 4646, 4736, 4826, 4916

Offset: 1

Author

Zak Seidov Jun 15 2003

Keywords

• easy
• nonn
• base

Comments

The two-digit terms here occur in many sequences, e.g., A066686, A081926, A017173, A030108, A043457, A052224, A061388, A084364.

Examples

			1469 and 6284 are members because 1+9=4+6=10 and 6+4=2+8=10.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..819 (All terms through 999999.)

Crossrefs

Cf. A066686, A081926, A017173, A030108, A043457, A052224, A061388, A084364.

Programs

Mathematica

ok10Q[n_]:=Module[{idn=IntegerDigits[n]},idn[[1]]+idn[[4]]==idn[[2]]+idn[[3]]==10]; Join[ Select[ Range[10,99],Total[IntegerDigits[#]]==10&],Select[Range[1000,9999],ok10Q]] (* Harvey P. Dale, Oct 14 2023 *)

PARI

isok(n) = {digs = digits(n); if (#digs % 2 == 0, for (i = 1, #digs/2, if ((digs[i] + digs[#digs+1-i]) ! = 10, return (0));); return (1);); return (0);} \\ Michel Marcus, Oct 05 2013