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.

A332967 Sum of all integers m satisfying Omega(m) = n and pi(p) <= n for all prime factors p of m.

Original entry on oeis.org

1, 2, 19, 410, 14343, 1139166, 89131918, 10861230692, 1271028562739, 203393524967230, 52274418436233714, 11160490802017899420, 3415612116240107778630, 1088775430914588654276060, 311608007930071575510930780, 99738699420765496000734958440
Offset: 0

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Author

Alois P. Heinz, Mar 04 2020

Keywords

Examples

			a(2) = 4 + 6 + 9 = 2*2 + 2*3 + 3*3 = 19.
		

Crossrefs

Row sums of A330394.
Main diagonal of A343751.

Programs

  • Maple
    b:= proc(n, i) option remember; `if`(n=0, 1,
          add(ithprime(j)*b(n-1, j), j=1..i))
        end:
    a:= n-> b(n$2):
    seq(a(n), n=0..17);

Formula

a(n) = [x^n] Product_{i=1..n} 1/(1-prime(i)*x).
a(n) = A124960(2n,n).
a(n) = Sum_{k=1..A088218(n)} A330394(n,k).
a(n) = A343751(n,n).