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.

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A014576 Smallest n-digit narcissistic (or Armstrong) number: smallest n-digit number equal to sum of n-th powers of its digits (or 0 if no such number exists).

Original entry on oeis.org

1, 0, 153, 1634, 54748, 548834, 1741725, 24678050, 146511208, 4679307774, 32164049650, 0, 0, 28116440335967, 0, 4338281769391370, 21897142587612075, 0, 1517841543307505039, 63105425988599693916, 128468643043731391252, 0
Offset: 1

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References

  • M. Gardner, The Magic Numbers of Dr Matrix. Prometheus, Buffalo, NY, 1985, p. 249.
  • C. A. Pickover, Keys to Infinity. New York: W. H. Freeman, pp. 169-170, 1995.

Crossrefs

Programs

  • Mathematica
    (* This program is not suitable for more than 10 terms *) a[n_] := For[k = 10^(n-1), True, k++, If[k > 10^n - 1, Return[0], If[k == Total[ IntegerDigits[k]^IntegerLength[k] ], Return[k] ] ] ]; Table[ Print[an = a[n]]; an, {n, 1, 10}] (* Jean-François Alcover, Oct 15 2013 *)

Extensions

Terms and links added by Patrick De Geest, Oct 1998
Broken links fixed by M. F. Hasler, Feb 12 2013

A033835 Smallest number > 1 equal to sum of n-th powers of its base-3 digits, or 0 if no such number exists (written in base 10).

Original entry on oeis.org

2, 5, 17, 0, 33, 66, 386, 258, 513, 1026, 0, 16388, 57345, 16389, 196610, 262149, 0, 786438, 3145733, 6291461, 0, 29360132, 0, 67108871, 234881030, 201326601, 1207959557, 2415919109, 3758096387, 5368709130, 10737418245, 30064771083
Offset: 1

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Crossrefs

Cf. A162216, A162217, A162218. In other bases: A033836 (base 4), A033837 (base 5), A033838 (base 6), A033839 (base 7), A033840 (base 8), A033841 (base 9), A003321 (base 10). - Joseph Myers, Jul 07 2009

A033836 Smallest number > 1 equal to sum of n-th powers of its base-4 digits, or 0 if no such number exists (written in base 10).

Original entry on oeis.org

2, 0, 8, 83, 32, 922, 128, 7330, 512, 0, 2048, 1075174, 8192, 0, 32768, 86486662, 131072, 776413846, 524288, 0, 2097152, 0, 8388608, 0, 33554432, 0, 134217728, 183016755558795, 536870912, 1029465324149666, 2147483648
Offset: 1

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Crossrefs

Cf. A162219, A162220, A162221. In other bases: A033835 (base 3), A033837 (base 5), A033838 (base 6), A033839 (base 7), A033840 (base 8), A033841 (base 9), A003321 (base 10). - Joseph Myers, Jul 07 2009

A033837 Smallest number > 1 equal to sum of n-th powers of its base-5 digits, or 0 if no such number exists (written in base 10).

Original entry on oeis.org

2, 13, 28, 289, 308, 4890, 257, 66562, 322217, 0, 0, 0, 16387, 268533762, 2204944815, 172449032, 34876823313, 207708636457, 0, 3315971951065, 8837942823632, 53027623387338, 422589088112942, 1129785254793
Offset: 1

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Cf. A162222, A162223, A162224. In other bases: A033835 (base 3), A033836 (base 4), A033838 (base 6), A033839 (base 7), A033840 (base 8), A033841 (base 9), A003321 (base 10). - Joseph Myers, Jul 07 2009

A033838 Smallest number > 1 equal to sum of n-th powers of its base-6 digits, or 0 if no such number exists (written in base 10).

Original entry on oeis.org

2, 0, 99, 0, 308, 36140, 269458, 391907, 10067135, 0, 0, 0, 1428423394, 0, 32693825124, 0, 797557733967, 11512812322194, 58598336876363, 192937380661240, 1443716084981654, 0, 36185564197761935
Offset: 1

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Cf. A162225, A162226, A162227. In other bases: A033835 (base 3), A033836 (base 4), A033837 (base 5), A033839 (base 7), A033840 (base 8), A033841 (base 9), A003321 (base 10). - Joseph Myers, Jul 07 2009

A033839 Smallest number > 1 equal to sum of n-th powers of its base-7 digits, or 0 if no such number exists (written in base 10).

Original entry on oeis.org

2, 10, 9, 0, 65, 35411, 37271, 72865, 2236488, 1110699, 416002778, 0, 5021821389, 0, 533453816220, 0, 18487285640920, 0, 1314916195476894, 0, 66773332795109537, 138809539743164589, 1591663132485308115, 14216271609499243850
Offset: 1

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Cf. A162228, A162229, A162230. In other bases: A033835 (base 3), A033836 (base 4), A033837 (base 5), A033838 (base 6), A033840 (base 8), A033841 (base 9), A003321 (base 10). - Joseph Myers, Jul 07 2009

Extensions

Extended by Joseph Myers, Jul 07 2009

A033840 Smallest number > 1 equal to sum of n-th powers of its base-8 digits, or 0 if no such number exists (written in base 10).

Original entry on oeis.org

2, 20, 92, 16, 1056, 212419, 128, 13379, 40695508, 1024, 4196352, 13892162580, 8192, 268451840, 1002493281672, 65536, 17180000256, 4998382669357032, 524288, 1099512676352, 3418993385062038719, 4194304, 70368752566272
Offset: 1

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Cf. A162231, A162232, A162233. In other bases: A033835 (base 3), A033836 (base 4), A033837 (base 5), A033838 (base 6), A033839 (base 7), A033841 (base 9), A003321 (base 10). - Joseph Myers, Jul 07 2009

Extensions

Extended by Joseph Myers, Jul 07 2009

A033841 Smallest number > 1 equal to sum of n-th powers of its base-9 digits, or 0 if no such number exists (written in base 10).

Original entry on oeis.org

2, 41, 27, 353, 243, 36804, 2187, 6287267, 19683, 403584750, 177147, 42256814922, 1594323, 1447031689954, 14348907, 320659684133768, 129140163, 117025292105903, 1162261467, 170554117891588216, 10460353203
Offset: 1

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Crossrefs

Cf. A162234, A162235, A162236. In other bases: A033835 (base 3), A033836 (base 4), A033837 (base 5), A033838 (base 6), A033839 (base 7), A033840 (base 8), A003321 (base 10). - Joseph Myers, Jul 07 2009

Extensions

Extended by Joseph Myers, Jul 07 2009

A052464 Fixed points for operation of repeatedly replacing a number with the sum of the fifth power of its digits.

Original entry on oeis.org

0, 1, 4150, 4151, 54748, 92727, 93084, 194979
Offset: 1

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Author

Henry Bottomley, Mar 15 2000

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Comments

Equivalently, numbers equal to the sum of 5th powers of their decimal digits. Since this sum is <= 9^5*d for a d-digit number n >= 10^(d-1), there cannot be such a number with more than 6 digits. - M. F. Hasler, Apr 12 2015

Examples

			a(2) = 4150 since 4^5 + 1^5 + 5^5 + 0^5 = 1024 + 1 + 3125 + 0 = 4150.
		

Crossrefs

Programs

A124068 Fixed points for operation of repeatedly replacing a number with the sum of the seventh power of its digits.

Original entry on oeis.org

0, 1, 1741725, 4210818, 9800817, 9926315, 14459929
Offset: 1

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Author

Sébastien Dumortier, Nov 05 2006

Keywords

Comments

The sequence "Fixed points for operation of repeatedly replacing a number by the sum of the sixth power of its digits" has just 3 terms: 0, 1, and 548834.
For a d-digit number n >= 10^(d-1), the sum of 7th powers of its digits is <= 9^7*d, therefore these numbers cannot exceed 41205040. - M. F. Hasler, Apr 12 2015

Examples

			1741725 = 1^7 + 7^7 + 4^7 + 1^7 + 7^7 + 2^7 + 5^7.
		

Crossrefs

Programs

  • PARI
    isok(n) = my(d = digits(n)); sum(k=1, #d, d[k]^7) == n; \\ Michel Marcus, Feb 21 2015
    
  • PARI
    for(n=0,41205040,A123253(n)==n&&print1(n",")) \\ M. F. Hasler, Apr 12 2015
Previous Showing 11-20 of 29 results. Next