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.

A378176 Sum over all multiplicative partitions mu of n (with factors > 1) of the encoding as Product_{j in mu} prime(j).

Original entry on oeis.org

1, 3, 5, 16, 11, 28, 17, 67, 48, 62, 31, 156, 41, 94, 102, 303, 59, 270, 67, 334, 158, 172, 83, 743, 218, 224, 343, 508, 109, 707, 127, 1173, 292, 316, 336, 1651, 157, 364, 372, 1587, 179, 1091, 191, 926, 960, 448, 211, 3468, 516, 1202, 528, 1198, 241, 2209
Offset: 1

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Author

Alois P. Heinz, Nov 18 2024

Keywords

Examples

			The multiplicative partitions of n=8 are {[8], [4,2], [2,2,2]}, encodings give {prime(8), prime(4)*prime(2), prime(2)^3} = {19, 7*3, 3^3} = {19, 21, 27}; the sum gives a(8) = 67.
		

Crossrefs

Programs

  • Maple
    b:= proc(n) option remember; `if`(n=1, {1}, {seq(map(x-> x*
          ithprime(d), b(n/d))[], d=numtheory[divisors](n) minus {1})})
        end:
    a:= n-> add(i, i=b(n)):
    seq(a(n), n=1..54);

Formula

a(prime(n)) = a(A000040(n)) = A006450(n).