cp's OEIS Frontend

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.

Showing 1-10 of 17 results. Next

A239037 a(n) = prime digit in A092621(n).

Original entry on oeis.org

2, 3, 5, 7, 3, 7, 2, 3, 3, 7, 5, 7, 7, 7, 3, 7, 3, 7, 3, 3, 3, 5, 3, 7, 7, 3, 7, 2, 2, 2, 2, 3, 3, 3, 2, 3, 3, 3, 3, 7, 7, 7, 5, 5, 5, 5, 7, 3, 7, 3, 3, 7, 5, 3, 7, 7, 7, 7, 7, 2, 2, 3, 5, 3, 3, 7, 7, 2, 7, 7, 7, 3, 7, 3, 2, 3, 3, 5, 3, 7, 3, 7, 3, 7, 2, 5, 3, 7, 7, 3, 2, 2, 2, 2, 3, 3, 3, 3, 3, 2, 3, 7, 5, 5, 7, 3, 7, 3, 5, 5, 7, 3, 2, 3, 7, 3, 7, 7, 7, 7, 3, 7, 7, 7, 7, 7, 3, 3, 5, 7, 7, 3, 7, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2
Offset: 1

Views

Author

Zak Seidov, Mar 09 2014

Keywords

Comments

From first 12000 terms, numbers of 2s, 3s, 5s, and 7s are: 2308, 3729, 2267, 3696. Note that numbers of 2s and 5s are very close to each other, and the same is for numbers of 3s and 7s.

Crossrefs

A179909 Primes with only one embedded prime.

Original entry on oeis.org

13, 17, 29, 31, 43, 47, 59, 67, 71, 79, 83, 97, 103, 107, 151, 163, 191, 199, 269, 281, 349, 421, 461, 463, 487, 509, 569, 607, 641, 661, 701, 709, 769, 787, 811, 821, 863, 877, 887, 907, 911, 919, 941, 1021, 1051, 1061, 1063, 1087, 1091, 1201, 1249, 1409
Offset: 1

Views

Author

Robert G. Wilson v, Aug 01 2010

Keywords

Comments

A079066(a(n)) = 1.

Crossrefs

Programs

  • Haskell
    import Data.List (elemIndices)
    a179909 n = a179909_list !! (n-1)
    a179909_list = map (a000040 . (+ 1)) $ elemIndices 1 a079066_list
    -- Reinhard Zumkeller, Jul 19 2011
  • Mathematica
    f[n_] := Block[ {id = IntegerDigits@n}, len = Length@ id - 1; Count[ PrimeQ@ Union[ FromDigits@# & /@ Flatten[ Table[ Partition[ id, k, 1], {k, len}], 1]], True] + 1]; Select[ Prime@ Range@ 230, f@# == 2 &]

A179919 Primes with eleven embedded primes.

Original entry on oeis.org

111317, 113177, 113537, 113719, 113731, 117193, 117331, 121379, 123733, 129719, 131797, 132173, 132971, 136733, 136739, 137197, 137321, 137339, 137353, 137359, 137393, 137573, 152311, 172313, 173137, 173359, 174311, 193373, 211319, 213799
Offset: 1

Views

Author

Robert G. Wilson v, Aug 01 2010

Keywords

Comments

A079066(a(n)) = 11.

Crossrefs

Programs

  • Haskell
    import Data.List (elemIndices)
    a179919 n = a179919_list !! (n-1)
    a179919_list = map (a000040 . (+ 1)) $ elemIndices 11 a079066_list
    -- Reinhard Zumkeller, Jul 19 2011
  • Mathematica
    f[n_] := Block[ {id = IntegerDigits@n}, len = Length@ id - 1; Count[ PrimeQ@ Union[ FromDigits@# & /@ Flatten[ Table[ Partition[ id, k, 1], {k, len}], 1]], True] + 1]; Select[ Prime@ Range@ 19110, f@# == 12 &]

A179922 Primes with twelve embedded primes.

Original entry on oeis.org

113171, 113173, 113797, 123719, 153137, 179719, 199739, 213173, 229373, 231197, 233113, 233713, 236779, 237331, 237619, 237971, 241973, 259397, 317971, 327193, 343373, 353173, 361373, 372719, 373379, 382373, 432713, 519733, 521137, 521317
Offset: 1

Views

Author

Robert G. Wilson v, Aug 01 2010

Keywords

Comments

A079066(a(n)) = 12.

Crossrefs

Programs

  • Haskell
    import Data.List (elemIndices)
    a179922 n = a179922_list !! (n-1)
    a179922_list = map (a000040 . (+ 1)) $ elemIndices 12 a079066_list
    -- Reinhard Zumkeller, Jul 19 2011
  • Mathematica
    f[n_] := Block[ {id = IntegerDigits@n}, len = Length@ id - 1; Count[ PrimeQ@ Union[ FromDigits@# & /@ Flatten[ Table[ Partition[ id, k, 1], {k, len}], 1]], True] + 1]; Select[ Prime@ Range@ 43150, f@# == 13 &]

A152426 Primes that have both prime digits (2,3,5,7) and nonprime digits (0,1,4,6,8,9).

Original entry on oeis.org

13, 17, 29, 31, 43, 47, 59, 67, 71, 79, 83, 97, 103, 107, 113, 127, 131, 137, 139, 151, 157, 163, 167, 173, 179, 193, 197, 211, 229, 239, 241, 251, 263, 269, 271, 281, 283, 293, 307, 311, 313, 317, 331, 347, 349, 359, 367, 379
Offset: 1

Views

Author

Omar E. Pol, Dec 03 2008

Keywords

Comments

See also A152427, a subsequence without zeros.

Crossrefs

Programs

  • Mathematica
    okQ[n_] := Module[{d=Union[IntegerDigits[n]]}, Length[Intersection[d, {2,3,5,7}]]>0 && Length[Intersection[d, {0,1,4,6,8,9}]]>0]; Select[Prime[Range[100]], okQ] (* T. D. Noe, Jan 20 2011 *)

Extensions

Edited by Omar E. Pol, Jul 04 2009, Jan 20 2011
Definition clarified by N. J. A. Sloane, Jul 05 2009

A152427 Primes that have both prime digits (2,3,5,7) and nonprime digits (1,4,6,8,9).

Original entry on oeis.org

13, 17, 29, 31, 43, 47, 59, 67, 71, 79, 83, 97, 103, 107, 113, 127, 131, 137, 139, 151, 157, 163, 167, 173, 179, 193, 197, 211, 229, 239, 241, 251, 263, 269, 271, 281, 283, 293, 311, 313, 317, 331, 347, 349, 359, 367, 379, 383, 389, 397, 421, 431, 433, 439
Offset: 1

Views

Author

Omar E. Pol, Dec 03 2008

Keywords

Comments

Crossrefs

Programs

  • Mathematica
    okQ[n_] := Module[{d = Union[IntegerDigits[n]]}, Length[Intersection[d, {2, 3, 5, 7}]] > 0 && Length[Intersection[d, {1, 4, 6, 8, 9}]] > 0]; Select[Prime[Range[100]], okQ] (* T. D. Noe, Jan 21 2011 *)
    pdQ[n_]:=Module[{idn=Select[IntegerDigits[n],#!=0&]},Count[idn,?PrimeQ]>0&&Count[idn,?(!PrimeQ[#]&)]>0]; Select[Prime[Range[100]],pdQ] (* Harvey P. Dale, Jan 31 2013 *)

Formula

a(n) ~ n log n

Extensions

Corrected and extended by Harvey P. Dale, Jan 31 2013

A179910 Primes with two embedded primes.

Original entry on oeis.org

23, 37, 53, 73, 127, 139, 157, 167, 193, 211, 227, 229, 241, 251, 263, 277, 307, 331, 383, 389, 419, 433, 439, 443, 457, 467, 503, 521, 541, 557, 563, 577, 587, 599, 619, 631, 643, 647, 659, 677, 683, 727, 751, 757, 761, 827, 829, 839, 857, 859, 883, 929
Offset: 1

Views

Author

Robert G. Wilson v, Aug 01 2010

Keywords

Comments

It appears that p having n embedded primes means that the set of prime integers generated by contiguous proper substrings of p has size n.
A079066(a(n)) = 2.

Crossrefs

Programs

  • Haskell
    import Data.List (elemIndices)
    a179910 n = a179910_list !! (n-1)
    a179910_list = map (a000040 . (+ 1)) $ elemIndices 2 a079066_list
    -- Reinhard Zumkeller, Jul 19 2011
  • Mathematica
    f[n_] := Block[ {id = IntegerDigits@n}, len = Length@ id - 1; Count[ PrimeQ@ Union[ FromDigits@# & /@ Flatten[ Table[ Partition[ id, k, 1], {k, len}], 1]], True] + 1]; Select[ Prime@ Range@ 160, f@# == 3 &]
    Select[ Prime@ Range@ 160, Function[ n, Length@ Select[ Union[ FromDigits /@ (Flatten[ Table[ Partition[#, k, 1], {k, Length@ # - 1}], 1] &)@ IntegerDigits@ n], PrimeQ]]@ # == 2 &] (* Michael Somos, Jan 13 2011 *)

A179911 Primes with three embedded primes.

Original entry on oeis.org

113, 131, 179, 197, 223, 233, 239, 257, 271, 283, 293, 311, 313, 337, 347, 353, 359, 367, 397, 431, 479, 547, 571, 593, 613, 617, 653, 719, 733, 739, 743, 773, 797, 823, 853, 937, 953, 971, 1013, 1031, 1097, 1103, 1117, 1129, 1151, 1163, 1213, 1217, 1229
Offset: 1

Views

Author

Robert G. Wilson v, Aug 01 2010

Keywords

Comments

A079066(a(n)) = 3.

Crossrefs

Programs

  • Haskell
    import Data.List (elemIndices)
    a179911 n = a179911_list !! (n-1)
    a179911_list = map (a000040 . (+ 1)) $ elemIndices 3 a079066_list
    -- Reinhard Zumkeller, Jul 19 2011
  • Mathematica
    f[n_] := Block[ {id = IntegerDigits@n}, len = Length@ id - 1; Count[ PrimeQ@ Union[ FromDigits@# & /@ Flatten[ Table[ Partition[ id, k, 1], {k, len}], 1]], True] + 1]; Select[ Prime@ Range@ 210, f@# == 4 &]

A179912 Primes with four embedded primes.

Original entry on oeis.org

137, 173, 317, 373, 379, 523, 673, 1123, 1153, 1171, 1193, 1223, 1231, 1277, 1279, 1283, 1297, 1307, 1327, 1531, 1579, 1597, 1613, 1637, 1759, 1783, 1823, 1913, 1931, 2053, 2153, 2333, 2339, 2341, 2351, 2393, 2399, 2411, 2467, 2503, 2539, 2543, 2557
Offset: 1

Views

Author

Robert G. Wilson v, Aug 01 2010

Keywords

Comments

A079066(a(n)) = 4.

Crossrefs

Programs

  • Haskell
    import Data.List (elemIndices)
    a179912 n = a179912_list !! (n-1)
    a179912_list = map (a000040 . (+ 1)) $ elemIndices 4 a079066_list
    -- Reinhard Zumkeller, Jul 19 2011
  • Mathematica
    f[n_] := Block[ {id = IntegerDigits@n}, len = Length@ id - 1; Count[ PrimeQ@ Union[ FromDigits@# & /@ Flatten[ Table[ Partition[ id, k, 1], {k, len}], 1]], True] + 1]; Select[ Prime@ Range@ 380, f@# == 5 &]

A179913 Primes with five embedded primes.

Original entry on oeis.org

1237, 1319, 1367, 1523, 1571, 1723, 1753, 1979, 1997, 2131, 2179, 2239, 2273, 2293, 2297, 2357, 2377, 2383, 2389, 2417, 2437, 2473, 2531, 2579, 2593, 2617, 2711, 2731, 2753, 2797, 3119, 3167, 3257, 3271, 3313, 3371, 3547, 3571, 3593, 3617, 3671, 3677
Offset: 1

Views

Author

Robert G. Wilson v, Aug 01 2010

Keywords

Comments

A079066(a(n)) = 5.

Crossrefs

Programs

  • Haskell
    import Data.List (elemIndices)
    a179913 n = a179913_list !! (n-1)
    a179913_list = map (a000040 . (+ 1)) $ elemIndices 5 a079066_list
    -- Reinhard Zumkeller, Jul 19 2011
  • Mathematica
    f[n_] := Block[ {id = IntegerDigits@n}, len = Length@ id - 1; Count[ PrimeQ@ Union[ FromDigits@# & /@ Flatten[ Table[ Partition[ id, k, 1], {k, len}], 1]], True] + 1]; Select[ Prime@ Range@ 510, f@# == 6 &]
Showing 1-10 of 17 results. Next