A365872
The "double commas" sequence, a variant of A121805. See the Comments and Example sections for detailed explanations.
Original entry on oeis.org
1, 25, 127, 271, 295, 403, 471, 499, 691, 725, 841, 877, 1019, 1201, 1223, 1285, 1387, 1529, 1711, 1733, 1795, 1897, 2041, 2065, 2169, 2353, 2417, 2561, 2585, 2689, 2873, 2937, 3083, 3149, 3335, 3441, 3467, 3613, 3679, 3865, 3971, 3997, 4145, 4253, 4321, 4349, 4537, 4685, 4793, 4861, 4889, 5079, 5269
Offset: 1
a(1) = 1 and a(2) = 25 are separated by 24 units, and 24 is twice 12 (or 1,2);
a(2) = 25 and a(3) = 127 are separated by 102 units, and 102 is twice 51 (or 5,1);
a(3) = 127 and a(4) = 271 are separated by 144 units, and 144 is twice 72 (or 7,2);
a(4) = 271 and a(5) = 295 are separated by 24 units, and 24 is twice 12 (or 1,2); etc.
-
a[1]=1;a[n_]:=a[n]=(k=a[n-1];While[2FromDigits@Join[{Mod[a[n-1],10]},{First@IntegerDigits@k}]!=k-a[n-1],k++];k);Array[a,70]
A365874
The "quadruple commas" sequence, a variant of A121805. See the Comments and Example sections for detailed explanations.
Original entry on oeis.org
1, 65, 273, 409, 797, 1081, 1125, 1329, 1693, 1817, 2105, 2313, 2441, 2489, 2857, 3149, 3521, 3573, 3705, 3917, 4213, 4349, 4725, 4941, 4997, 5297, 5597, 5897, 6201, 6265, 6489, 6873, 7021, 7089, 7477, 7785, 8017, 8329, 8721, 8793, 8945, 9181, 9257, 9573, 9729, 10093, 10217, 10501, 10545, 10749, 11113
Offset: 1
a(1) = 1 and a(2) = 65 are separated by 64 units, and 64 is 4*16 (or 1,6);
a(2) = 65 and a(3) = 273 are separated by 208 units, and 208 is 4*52 (or 5,2);
a(3) = 273 and a(4) = 409 are separated by 136 units, and 136 is 4*34 (or 3,4);
a(4) = 409 and a(5) = 797 are separated by 388 units, and 388 is 4*97 (or 9,7); etc.
-
a[1]=1;a[n_]:=a[n]=(k=a[n-1];While[4FromDigits@Join[{Mod[a[n-1],10]},{First@IntegerDigits@k}]!=k-a[n-1],k++];k);Array[a,70]
A365875
The "reversed commas" sequence, a variant of A121805. See the Comments and Example sections for detailed explanations.
Original entry on oeis.org
1, 92, 104, 118, 136, 152, 164, 178, 206, 232, 254, 278, 316, 352, 384, 428, 476, 532, 584, 648, 726, 812, 904, 998, 1016, 1032, 1044, 1058, 1076, 1092, 1104, 1118, 1136, 1152, 1164, 1178, 1196, 1212, 1224, 1238, 1256, 1272, 1284, 1298, 1316, 1332, 1344, 1358, 1376, 1392, 1404, 1418, 1436, 1452, 1464
Offset: 1
After a(1) = 1, we have multiple choices for a(2); they are 12, 22, 32, 42, 52, 62, 72, 82 and 92. We keep 92 for a(2) as 92 is the largest term.
a(1) = 1 and a(2) = 92 are separated by 91 units, and 91 is 19 backwards (or 1,9);
a(2) = 92 and a(3) = 104 are separated by 12 units, and 12 is 21 backwards (or 2,1);
a(3) = 104 and a(4) = 118 are separated by 14 units, and 14 is 41 backwards (or 4,1);
a(4) = 118 and a(5) = 136 are separated by 18 units, and 18 is 81 backwards (or 8,1); etc.
The next choices we encountered (keeping the largest term) were after a(8) = 178 -> {196,206}, then after 812 -> {894,904}, 1976 -> {1992,2002}, 3956 -> {3992,4002}, 19984 -> {19998,20008}, 39958 -> {39996,40006}, 49952 -> {49994,50004}, etc.
-
NestList[(s=#;li=First@*IntegerDigits/@Table[s+10*k+Mod[s,10],{k,9}]-Range@9;
Last@Table[s+FromDigits@Join[Position[li,0][[c]],{Mod[s,10]}],{c,Length@Position[li,0]}])&,1,2513]
Showing 1-3 of 3 results.
Comments