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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A045816 Number of times the digits are repeated in A045815.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 8, 4, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 6
Offset: 1

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Examples

			Divisors of 20345 are (1,20345), the numbers of digits are [0(1),1(1),2(1),3(1),4(1),5(1)], so a(1) = 1.
Divisors of 45050 are (1,2,3,10,4505,13414,22323,45050), the numbers of digits (0-5) are [0(4),1(4),2(4),3(4),4(4),5(4)], so a(10) = 4.
		

Crossrefs

Programs

  • Maple
    isA045816 := proc(n) local c,j,b,h,a ; a := [0,0,0,0,0,0] : c := numtheory[divisors](n): for j from 1 to nops(c) do b := convert(c[j], base, 6); for h from 1 to nops(b) do a[b[h]+1] := a[b[h]+1]+1: end do: end do: if(a[1]=a[2] and a[2]=a[3] and a[3]=a[4] and a[4]=a[5] and a[5]=a[6]) then a[1] ; else -1 ; end if: end: n := 1: while true do a := isA045816(n) : if a >= 0 then printf("%d, ",a) ; fi ; n := n+1 : od : # R. J. Mathar, Jun 26 2007

Extensions

More terms from Sean A. Irvine, Sep 26 2011

A045869 Integers k such that in the list of divisors of k (in base 5), each digit 0-4 appears equally often.

Original entry on oeis.org

2034, 2403, 2430, 3024, 3042, 3240, 3304, 3340, 3420, 4203, 4230, 4302, 4320, 4330, 4340, 213330, 303240, 310430, 330101, 1230134, 1240404, 1303034, 1322340, 1330304, 1340303, 1343030, 2000434, 2004120, 2244030, 2420401, 3020002
Offset: 1

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A045870 Number of times the digits are repeated in A045869.

Original entry on oeis.org

1, 1, 2, 1, 1, 2, 2, 4, 2, 2, 2, 1, 6, 4, 4, 8, 8, 8, 4, 3, 6, 3, 12, 3, 3, 6, 6, 12, 12, 6, 6, 10, 10, 10, 5, 10, 5, 5, 20, 5, 10, 7, 14, 28, 22, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 22, 2, 2, 2, 4, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4, 2, 4, 2, 2
Offset: 0

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Examples

			A045869(1) = 2034, and the divisors of 2034_5 = 269 (a prime) are 1 and 269; in base 5, these are 1 and 2034. Each digit from 0 through 4 appears exactly once, so a(1) = 1.
A045869(2) = 2403; 2403_5 = 353 (a prime) has divisors 1 and 353, which in base 5 are 1 and 2403, so each digit in 0..4 appears exactly once, so a(2) = 2.
A045869(3) = 2430; 2430_5 = 365 = 5*73, so its divisors are 1, 5, 73, and 365, which in base 5 are 1, 10, 243, and 2430, so each digit in 0..4 appears exactly twice, so a(3) = 2.
		

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Extensions

Examples edited by Jon E. Schoenfield, Nov 12 2022

A045871 Numbers n with the property that in the list of divisors of n (in octal), each digit 0-7 appears equally often.

Original entry on oeis.org

2035467, 2037465, 2046375, 2046573, 2047365, 2047563, 2056743, 2057643, 2063457, 2063475, 2067345, 2074365, 2074635, 2075463, 2076345, 2076453, 2307645, 2347065, 2356047, 2360547, 2364075, 2365407, 2406537, 2407365, 2407653, 2430675, 2436075
Offset: 1

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Examples

			Divisors of 2035467 are (1,2035467); the numbers of digits (0-7) are [ 0(1),1(1),2(1),3(1),4(1),5(1),6(1),7(1) ].
		

Crossrefs

Extensions

Missing terms inserted by Sean A. Irvine, Mar 22 2021
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