A083678 Numbers n = 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

1,1

Comments

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

Links

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

Example

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

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 *)

Prog

(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

Crossrefs

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

Sequence in context: A052224 A179955 A243994 * A279771 A257043 A369341

Adjacent sequences: A083675 A083676 A083677 * A083679 A083680 A083681

Keyword

easy,nonn,base

Author

Zak Seidov Jun 15 2003

Status

approved