A113514 First number in the descending sequence associated with A114758.
1, 2, 5, 7, 17, 12, 9, 8, 9, 24, 11, 113, 55, 19, 22, 60, 40, 38, 42, 73
Offset: 1
This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
a(2) = 10111= 10 followed by 11 followed by 1. a(3) = 1231, three successive positive integers 1,2,3 in ascending order followed by a 1.
a[n_]:=(For[m=1, (v={};Do[v=Join[v, IntegerDigits[k]], {k, m, m+n-1}]);!PrimeQ[10FromDigits[v]+1], m++ ];10FromDigits[v]+1);Table[a[n], {n, 14}] - Farideh Firoozbakht
f[n_] := Block[{t = Range@n}, While[p = FromDigits@Flatten@IntegerDigits@Join[t, {1}]; !PrimeQ@p, t++ ]; p]; Array[f, 13] (* Robert G. Wilson v *)
a(4) = 12347, four successive positive integers 1,2,3,4 in ascending order followed by a 7.
a[n_]:=(For[m=1, (v={};Do[v=Join[v, IntegerDigits[k]], {k, m, m+n-1}]);!PrimeQ[10FromDigits[v]+7], m++ ];10FromDigits[v]+7);Table[a[n], {n, 14}] - Farideh Firoozbakht
f[n_] := Block[{t = Range@n}, While[p = FromDigits@Flatten@IntegerDigits@Join[t, {7}]; !PrimeQ@p, t++ ]; p]; Array[f, 14] (* Robert G. Wilson v *)
Table[SelectFirst[10 FromDigits[Flatten[IntegerDigits/@#]]+7&/@ Partition[ Range[1000],n,1],PrimeQ],{n,20}] (* Harvey P. Dale, Jan 29 2022 *)
a(2) = 439, two successive positive integers 4,3 in descending order followed by a 9. a(4) = 262524239 four successive positive integers 26,25,24,23 in descending order followed by a 9.
a[n_]:=If[Mod[n, 3]==0, 0, (For[m=1, (v={};Do[v=Join[v, IntegerDigits[k]], {k, m+n-1, m, -1}]);!PrimeQ[10FromDigits[v]+9], m++ ];10FromDigits[v]+9)];Table[a[n], {n, 16}] (* Farideh Firoozbakht *)
f[n_] := Block[{t = Reverse@Range@n}, If[ Mod[n, 3] == 0, 0, While[p = FromDigits@Flatten@IntegerDigits@Join[t, {9}]; !PrimeQ@p, t++ ]; p]]; Array[f, 16] (* Robert G. Wilson v *)
a(4) = 65437, four successive positive integers 6,5,4,3 in descending order followed by a 7.
a[n_]:=(For[m=1, (v={};Do[v=Join[v, IntegerDigits[k]], {k, m+n-1, m, -1}]);!PrimeQ[10FromDigits[v]+7], m++ ];10FromDigits[v]+7);Table[a[n], {n, 14}] - Farideh Firoozbakht
f[n_] := Block[{t = Reverse@Range@n}, While[p = FromDigits@Flatten@IntegerDigits@Join[t, {7}]; !PrimeQ@p, t++ ]; p]; Array[f, 14] (* Robert G. Wilson v *)
a(4) = 12343, four successive positive integers 1,2,3,4 in ascending order followed by a 3.
a[n_]:=If[Mod[n, 3]==0, 0, (For[m=1, (v={};Do[v=Join[v, IntegerDigits[k]], {k, m, m+n-1}]);!PrimeQ[10FromDigits[v]+3], m++ ];10FromDigits[v]+3)];Table[a[n], {n, 17}] - Farideh Firoozbakht
f[n_] := Block[{t = Range@n}, If[ Mod[n, 3] == 0, 0, While[p = FromDigits@Flatten@IntegerDigits@Join[t, {3}]; !PrimeQ@p, t++ ]; p]]; Array[f, 20] (* Robert G. Wilson v *)
a(4) = 23459, four successive positive integers 2,3,4,5 in ascending order followed by a 9.
a[n_]:=If[Mod[n, 3]==0, 0, (For[m=1, (v={};Do[v=Join[v, IntegerDigits[k]], {k, m, m+n-1}]);!PrimeQ[10FromDigits[v]+9], m++ ];10FromDigits[v]+9)];Table[a[n], {n, 17}] - Farideh Firoozbakht
f[n_] := Block[{t = Range@n}, If[ Mod[n, 3] == 0, 0, While[p = FromDigits@Flatten@IntegerDigits@Join[t, {9}]; !PrimeQ@p, t++ ]; p]]; Array[f, 16] (* Robert G. Wilson v *)
a(4) = 54323, four successive positive integers 5,4,3,2 in descending order followed by a 3.
a[n_]:=If[Mod[n, 3]==0, 0, (For[m=1, (v={};Do[v=Join[v, IntegerDigits[k]], {k, m+n-1, m, -1}]);!PrimeQ[10FromDigits[v]+3], m++ ];10FromDigits[v] +3)];Table[a[n], {n, 17}] - Farideh Firoozbakht
f[n_] := Block[{t = Reverse@Range@n}, If[Mod[n, 3] == 0, 0, While[p = FromDigits@Flatten@IntegerDigits@Join[t, {3}]; ! PrimeQ@p, t++ ]; p]]; Array[f, 18] (* Robert G. Wilson v *)