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 11 results. Next

A308248 Squares of automorphic numbers in base 6 (cf. A237583).

Original entry on oeis.org

0, 1, 9, 16, 81, 784, 6561, 18496, 1478656, 43046721, 281165824, 893352321, 5859137025, 41368305664, 405026597889, 1088266240000, 15965210931201, 36991307874304, 583272781383681, 1318789102698496
Offset: 1

Views

Author

Jeremias M. Gomes, May 17 2019

Keywords

Examples

			784 = 3344_6 and sqrt(3344_6) = 44_6. Hence 784 is in the sequence.
		

Crossrefs

Cf. A237583.

Programs

  • Sage
    [(n * n) for n in (0..1000000) if (n * n).str(base = 6).endswith(n.str(base = 6))]

Formula

a(n) = A237583(n)^2. - Michel Marcus, May 17 2019

A201821 Automorphic numbers: n^2 ends with n in base 6 (written in base 6).

Original entry on oeis.org

0, 1, 3, 4, 13, 44, 213, 344, 5344, 50213, 205344, 350213, 1350213, 4205344, 21350213, 34205344, 221350213, 334205344, 2221350213, 3334205344, 52221350213, 152221350213, 403334205344, 5152221350213, 55152221350213, 155152221350213, 400403334205344
Offset: 1

Views

Author

Martin Renner, Dec 06 2011

Keywords

Examples

			a(3) = (3)_6 = 3 since 3^2 = 9 = (13)_6 ends with 3 in base 6.
a(4) = (4)_6 = 4 since 4^2 = 16 = (24)_6 ends with 4 in base 6.
a(5) = (13)_6 = 9 since 9^2 = 81 = (213)_6 ends with 13 in base 6.
		

References

  • Albert H. Beiler, Recreations in the theory of numbers, New York, Dover, (2nd ed.) 1966, p. 147.
  • Maurice Kraitchik, Mathematical Recreations, New York, Dover, (2nd ed.) 1953, p. 77.

Crossrefs

Cf. A237583 (written in base 10), A003226, A201918, A201919, A201921, A201948.

Extensions

More terms from Eric M. Schmidt, Feb 09 2014

A201919 Automorphic numbers n^2 ends with n in base 14 (written in base 10).

Original entry on oeis.org

0, 1, 7, 8, 49, 148, 344, 2401, 36016, 151264, 386561, 1764736, 5764801, 46941952, 58471553, 374712065, 1101076992, 4802079233, 15858967552, 139825248256, 149429406721, 1595702681601, 2453862488064, 14602557997056, 42091354378241, 127990382747648
Offset: 1

Views

Author

Martin Renner, Dec 06 2011

Keywords

Examples

			a(3) = 7 = (7)_14 since 7^2 = 49 = (37)_14 ends with 7 in base 14.
a(4) = 8 = (8)_14 since 8^2 = 64 = (48)_14 ends with 8 in base 14.
a(5) = 49 = (37)_14 since 49^2 = 2401 = (C37)_14 ends with 37 in base 14.
		

Crossrefs

Programs

Extensions

More terms from Eric M. Schmidt, Feb 09 2014

A201918 Automorphic numbers: n^2 ends with n in base 12 (written in base 10).

Original entry on oeis.org

0, 1, 4, 9, 64, 81, 513, 1216, 6400, 14337, 234496, 483328, 2502657, 17432577, 18399232, 412549120, 842530816, 4317249537, 11162091520, 50755272705, 692253097984, 2178269839360, 6737830608897, 46758772080640, 60234433298433, 474731593596928, 809186870951937
Offset: 1

Views

Author

Martin Renner, Dec 06 2011

Keywords

Examples

			a(3) = 4 = (4)_12 since 4^2 = 16 = (14)_12 ends with 4 in base 12.
a(4) = 9 = (9)_12 since 9^2 = 81 = (69)_12 ends with 9 in base 12.
a(5) = 64 = (54)_12 since 64^2 = 4096 = (2454)_12 ends with 54 in base 12.
		

Crossrefs

Programs

  • Mathematica
    a201918[n_Integer] := Module[{i = 0}, Flatten[Last[Reap[
         Do[If[
           IntegerDigits[i^2, 12][[-Length[IntegerDigits[i, 12]] ;; -1]] ==
             IntegerDigits[i, 12], Sow[i]], {i, n}]]]]]; a201918[12^6] (* Michael De Vlieger, Aug 13 2014 *)
  • Sage
    # See A003226. - Eric M. Schmidt, Feb 09 2014

Extensions

More terms from Eric M. Schmidt, Feb 09 2014

A201921 Automorphic numbers: n^2 ends with n in base 15 (written in base 10).

Original entry on oeis.org

0, 1, 6, 10, 100, 126, 1000, 2376, 4375, 46251, 156250, 603126, 3640626, 7750000, 19140625, 151718751, 835156251, 1727734375, 5960937501, 32482421875, 236621093751, 340029296875, 8413134765625, 60784912109376, 68961425781250, 709516601562501, 1236678466796875
Offset: 1

Views

Author

Martin Renner, Dec 06 2011

Keywords

Examples

			a(3) = 6 = (6)_15 since 6^2 = 36 = (26)_15 ends with 6 in base 15.
a(4) = 10 = (A)_15 since 10^2 = 100 = (6A)_15 ends with A in base 15.
a(5) = 100 = (6A)_15 since 100^2 = 10000 = (2E6A)_15 ends with 6A in base 15.
		

Crossrefs

Programs

Extensions

More terms from Eric M. Schmidt, Feb 09 2014

A201948 Automorphic numbers: n^2 ends with n in base 18 (written in base 10).

Original entry on oeis.org

0, 1, 9, 10, 81, 244, 729, 5104, 6561, 98416, 413344, 1476225, 9034497, 24977728, 263063296, 349156737, 2711943424, 8308017153, 96467701761, 101891588608, 1286623443969, 2283843782656, 30847581595648, 33420828483585, 352189631991808, 804641749434369
Offset: 1

Views

Author

Martin Renner, Dec 06 2011

Keywords

Examples

			a(3) = 9 = (9)_18 since 9^2 = 81 = (49)_18 ends with 9 in base 18.
a(4) = 10 = (A)_18 since 10^2 = 100 = (5A)_18 ends with A in base 18.
a(5) = 81 = (49)_18 since 81^2 = 6561 = (1249)_18 ends with 49 in base 18.
		

Crossrefs

Programs

Extensions

More terms from Eric M. Schmidt, Feb 09 2014

A259986 This sequence and A259987 are base-6 analogs of A007185 and A016090, written in base 10.

Original entry on oeis.org

3, 9, 81, 81, 6561, 29889, 76545, 636417, 3995649, 24151041, 326481921, 689278977, 11573190657, 76876660737, 155240824833, 2035980763137, 4857090670593, 55637069004801, 157197025673217, 1375916505694209, 19656708706009089, 129341461907898369
Offset: 1

Views

Author

N. J. A. Sloane, Jul 13 2015

Keywords

Comments

See Schut (1991) for precise definition.
Ignoring repetitions, the subsequence of A237583 of terms ending in 3 in base 6. - Eric M. Schmidt, Jul 18 2015

References

  • C. P. Schut, Idempotents. Report AM-R9101, Centrum voor Wiskunde en Informatica, Amsterdam, 1991.

Crossrefs

Programs

  • Sage
    def a(n) : return crt(1, 0, 2^n, 3^n) # Eric M. Schmidt, Jul 18 2015

Extensions

More terms from Eric M. Schmidt, Jul 18 2015

A259987 This sequence and A259986 are base 6 analogs of A007185 and A016090, written in base 10.

Original entry on oeis.org

4, 28, 136, 1216, 1216, 16768, 203392, 1043200, 6082048, 36315136, 36315136, 1487503360, 1487503360, 1487503360, 314944159744, 785129144320, 12069568774144, 45922887663616, 452162714337280, 2280241934368768, 2280241934368768, 2280241934368768, 2280241934368768
Offset: 1

Views

Author

N. J. A. Sloane, Jul 13 2015

Keywords

Comments

See Schut (1991) for precise definition.
Ignoring repetitions, the subsequence of A237583 of terms ending in 4 in base 6. - Eric M. Schmidt, Jul 18 2015

References

  • C. P. Schut, Idempotents. Report AM-R9101, Centrum voor Wiskunde en Informatica, Amsterdam, 1991.

Crossrefs

Programs

  • Sage
    def a(n) : return crt(0, 1, 2^n, 3^n) # Eric M. Schmidt, Jul 18 2015

Extensions

More terms from Eric M. Schmidt, Jul 18 2015

A259988 This sequence and A259989 are base-6 analogs of A007185 and A016090, written in base 6.

Original entry on oeis.org

3, 13, 213, 213, 50213, 350213, 1350213, 21350213, 221350213, 2221350213, 52221350213, 152221350213, 5152221350213, 55152221350213, 155152221350213, 4155152221350213, 14155152221350213, 314155152221350213, 1314155152221350213, 21314155152221350213
Offset: 1

Views

Author

N. J. A. Sloane, Jul 13 2015

Keywords

Comments

See Schut (1991) for precise definition.
Ignoring repetitions, the subsequence of A201821 of terms ending in 3. - Eric M. Schmidt, Jul 18 2015

References

  • C. P. Schut, Idempotents. Report AM-R9101, Centrum voor Wiskunde en Informatica, Amsterdam, 1991.

Crossrefs

Programs

  • Sage
    def a(n) : return Integer(crt(1, 0, 2^n, 3^n).str(6)) # Eric M. Schmidt, Jul 18 2015

Extensions

More terms from Eric M. Schmidt, Jul 18 2015

A259989 This sequence and A259988 are base-6 analogs of A007185 and A016090, written in base 6.

Original entry on oeis.org

4, 44, 344, 5344, 5344, 205344, 4205344, 34205344, 334205344, 3334205344, 3334205344, 403334205344, 403334205344, 403334205344, 400403334205344, 1400403334205344, 41400403334205344, 241400403334205344, 4241400403334205344, 34241400403334205344
Offset: 1

Views

Author

N. J. A. Sloane, Jul 13 2015

Keywords

Comments

See Schut (1991) for precise definition.
Ignoring repetitions, the subsequence of A201821 of terms ending in 4. - Eric M. Schmidt, Jul 18 2015

References

  • C. P. Schut, Idempotents. Report AM-R9101, Centrum voor Wiskunde en Informatica, Amsterdam, 1991.

Crossrefs

Programs

  • Sage
    def a(n) : return Integer(crt(0, 1, 2^n, 3^n).str(6)) # Eric M. Schmidt, Jul 18 2015

Extensions

Corrected and extended by Eric M. Schmidt, Jul 18 2015
Showing 1-10 of 11 results. Next