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 1-3 of 3 results.

A124069 Fixed points for operation of repeatedly replacing a number with the sum of the eighth power of its digits.

Original entry on oeis.org

0, 1, 24678050, 24678051, 88593477
Offset: 1

Views

Author

Sébastien Dumortier, Nov 05 2006

Keywords

Comments

This is row n=8 of A252648. For a d-digit number n >= 10^(d-1), the sum of 8th powers of its digits is <= 9^8*d, therefore n <= 413979400. - M. F. Hasler, Apr 12 2015

Examples

			24678050 = 2^8 + 4^8 + 6^8 + 7^8 + 8^8 + 0^8 + 5^8 + 0^8.

Crossrefs

Cf. A046197, A052455, A052464, A124068, A226970, A003321, A210840, A252648.

Programs

  • PARI
    isok(n) = my(d = digits(n)); sum(k=1, #d, d[k]^8) == n; \\ Michel Marcus, Feb 21 2015
  • PARI
    for(n=0,413979400,A210840(n)==n&&print1(n",")) \\ M. F. Hasler, Apr 12 2015

Formula

a(n) = A210840(a(n)). - M. F. Hasler, Apr 12 2015

A123253 Sum of 7th powers of digits of n.

Original entry on oeis.org

0, 1, 128, 2187, 16384, 78125, 279936, 823543, 2097152, 4782969, 1, 2, 129, 2188, 16385, 78126, 279937, 823544, 2097153, 4782970, 128, 129, 256, 2315, 16512, 78253, 280064, 823671, 2097280, 4783097, 2187, 2188, 2315, 4374, 18571, 80312, 282123
Offset: 0

Views

Author

Zerinvary Lajos, Nov 06 2006

Keywords

Comments

Fixed points are listed in A124068 = row n=7 of A252648. - M. F. Hasler, Apr 12 2015

Links

Crossrefs

Cf. A003132, A055012, A055013, A055014, A055015, A210840.

Programs

  • Magma
    [0] cat [&+[d^7: d in Intseq(n)]: n in [1..40]]; // Bruno Berselli, Feb 01 2013
  • Maple
    A123253 := proc(n)
        add(d^7,d=convert(n,base,10)) ;
end proc: # R. J. Mathar, Jan 16 2013
  • Mathematica
    Table[Sum[DigitCount[n][[i]] i^7, {i, 9}], {n, 0, 40}] (* Bruno Berselli, Feb 01 2013 *)
  • PARI
    A123253(n)=sum(i=1,#n=digits(n),n[i]^7) \\ M. F. Hasler, Apr 12 2015

A355708 Irregular triangle read by rows in which row n lists the possible periods for the iterations of the map sum of n-th powers of digits.

Original entry on oeis.org

1, 1, 8, 1, 2, 3, 1, 2, 7, 1, 2, 4, 6, 10, 12, 22, 28, 1, 2, 3, 4, 10, 30, 1, 2, 3, 6, 12, 14, 21, 27, 30, 56, 92, 1, 25, 154, 1, 2, 3, 4, 8, 10, 19, 24, 28, 30, 80, 93, 1, 6, 7, 17, 81, 123
Offset: 1

Views

Author

Mohammed Yaseen, Jul 14 2022

Keywords

Examples

			Triangle begins:
  1;
  1, 8;
  1, 2, 3;
  1, 2, 7;
  1, 2, 4, 6, 10, 12, 22, 28;
  1, 2, 3, 4, 10, 30;
  1, 2, 3, 6, 12, 14, 21, 27, 30, 56, 92;
  1, 25, 154;
  1, 2, 3, 4, 8, 10, 19, 24, 28, 30, 80, 93;
  1, 6, 7, 17, 81, 123;
  ...

Links

Crossrefs

Periods of sum of m-th powers of digits iterated: A031176 (m=2), A031178 (m=3), A031182 (m=4), A031186 (m=5), A031195 (m=6), A031200 (m=7), A031211 (m=8), A031212 (m=9), A031213 (m=10).
Sum of m-th powers of digits: A007953 (m=1), A003132 (m=2), A055012 (m=3), A055013 (m=4), A055014 (m=5), A055015 (m=6), A123253 (m=7), A210840 (m=8).
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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