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.

A115333 Sum of primes that do not divide n and are less than the largest prime dividing n.

Original entry on oeis.org

0, 0, 2, 0, 5, 0, 10, 0, 2, 3, 17, 0, 28, 8, 2, 0, 41, 0, 58, 3, 7, 15, 77, 0, 5, 26, 2, 8, 100, 0, 129, 0, 14, 39, 5, 0, 160, 56, 25, 3, 197, 5, 238, 15, 2, 75, 281, 0, 10, 3, 38, 26, 328, 0, 12, 8, 55, 98, 381, 0, 440, 127, 7, 0, 23, 12, 501, 39, 74, 3, 568, 0, 639, 158, 2, 56, 10
Offset: 1

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Author

Leroy Quet, Mar 05 2006

Keywords

Comments

When n is prime, n = largest prime dividing n; hence a(n) is the sum of all primes less than n = A034387(n)-n. a(n) = SUM{p such that p is in A000040 AND NOT(p|n) AND p < A006530(n)}. - Jonathan Vos Post, Mar 08 2006
The zeros give A055932: All prime divisors are consecutive primes starting at 2. - Robert G. Wilson v, May 01 2006

Examples

			The primes < 7 and coprime to 7 are 2, 3 and 5. So a(7) = 2+3+5 = 10.
		

Crossrefs

Programs

  • Mathematica
    f[n_] := Plus @@ Complement[Prime@ Range@ PrimePi[ Max[First /@ FactorInteger@n] - 1], First /@ FactorInteger@n]; Array[f, 77] (* Hans Havermann, Mar 06 2006 *)

Extensions

More terms from Hans Havermann, Mar 06 2006