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 1-4 of 4 results.

A218736 a(n) = (33^n - 1)/32.

Original entry on oeis.org

0, 1, 34, 1123, 37060, 1222981, 40358374, 1331826343, 43950269320, 1450358887561, 47861843289514, 1579440828553963, 52121547342280780, 1720011062295265741, 56760365055743769454, 1873092046839544391983, 61812037545704964935440, 2039797239008263842869521
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 33 (A009977).

Crossrefs

Programs

Formula

From Vincenzo Librandi, Nov 07 2012: (Start)
G.f.: x/((1 - x)*(1 - 33*x)).
a(n) = 34*a(n-1) - 33*a(n-2).
a(n) = floor(33^n/32). (End)
E.g.f.: exp(x)*(exp(32*x) - 1)/32. - Stefano Spezia, Mar 24 2023

A100403 Digital root of 6^n.

Original entry on oeis.org

1, 6, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9
Offset: 0

Views

Author

Cino Hilliard, Dec 31 2004

Keywords

Comments

Also the digital root of k^n for any k == 6 (mod 9). - Timothy L. Tiffin, Dec 02 2023

Examples

			For n=8, the digits of 6^8 = 1679616 sum to 36, whose digits sum to 9. So, a(8) = 9. - _Timothy L. Tiffin_, Dec 01 2023
		

Crossrefs

Programs

  • Mathematica
    PadRight[{1, 6}, 100, 9] (* Timothy L. Tiffin, Dec 03 2023 *)
  • PARI
    a(n) = if( n<2, [1,6][n+1], 9); \\ Joerg Arndt, Dec 03 2023

Formula

From Timothy L. Tiffin, Dec 01 2023: (Start)
a(n) = 9 for n >= 2.
G.f.: (1+5x+3x^2)/(1-x).
a(n) = A100401(n) for n <> 1.
a(n) = A010888(A000400(n)) = A010888(A001024(n)) = A010888(A009968(n)) = A010888(A009977(n)) = A010888(A009986(n)) = A010888(A159991(n)). (End)
E.g.f.: 9*exp(x) - 3*x - 8. - Elmo R. Oliveira, Aug 09 2024
a(n) = A007953(6*a(n-1)) = A010888(6*a(n-1)). - Stefano Spezia, Mar 20 2025

A264871 Array read by antidiagonals: T(n,m) = (1+2^n)^m; n,m>=0.

Original entry on oeis.org

1, 2, 1, 4, 3, 1, 8, 9, 5, 1, 16, 27, 25, 9, 1, 32, 81, 125, 81, 17, 1, 64, 243, 625, 729, 289, 33, 1, 128, 729, 3125, 6561, 4913, 1089, 65, 1, 256, 2187, 15625, 59049, 83521, 35937, 4225, 129, 1, 512, 6561, 78125, 531441, 1419857, 1185921, 274625, 16641, 257
Offset: 0

Views

Author

R. J. Mathar, Nov 27 2015

Keywords

Examples

			       1,       2,       4,       8,      16,      32,
       1,       3,       9,      27,      81,     243,
       1,       5,      25,     125,     625,    3125,
       1,       9,      81,     729,    6561,   59049,
       1,      17,     289,    4913,   83521, 1419857,
       1,      33,    1089,   35937, 1185921,39135393,
		

Crossrefs

Cf. A000079 (row 0), A000244 (row 1), A000351 (row 2), A001019 (row 3), A001026 (row 4), A009977 (row 5), A000051 (column 1), A028400 (column 2), A136516 (main diagonal), A165327 (upper subdiagonal).

Programs

  • Mathematica
    Reverse /@ Table[(1 + 2^(n - m))^m, {n, 0, 9}, {m, 0, n}] // Flatten (* Michael De Vlieger, Nov 27 2015 *)

Formula

G.f. for row n: 1/(1-(1+2^n)*x). - R. J. Mathar, Dec 15 2015

A165854 Totally multiplicative sequence with a(p) = 33.

Original entry on oeis.org

1, 33, 33, 1089, 33, 1089, 33, 35937, 1089, 1089, 33, 35937, 33, 1089, 1089, 1185921, 33, 35937, 33, 35937, 1089, 1089, 33, 1185921, 1089, 1089, 35937, 35937, 33, 35937, 33, 39135393, 1089, 1089, 1089, 1185921, 33, 1089, 1089, 1185921, 33, 35937, 33
Offset: 1

Views

Author

Jaroslav Krizek, Sep 28 2009

Keywords

Programs

  • Mathematica
    33^PrimeOmega[Range[50]] (* Harvey P. Dale, Oct 02 2015 *)
  • PARI
    a(n) = 33^bigomega(n); \\ Altug Alkan, Apr 15 2016

Formula

a(n) = A009977(A001222(n)) = 33^bigomega(n) = 33^A001222(n).
Showing 1-4 of 4 results.