Proof step `e-b6c6a979053116b3`

preserver_image derivative_polynomial, shift 0 → concludes about a(n) = 1 if n is a triangular number, otherwise 0. JSON

Theorem

Laguerre’s theorem on differential operators [SP14] polytool ?

Lean (RealRooted): RealRooted.splits_add_C_mul_derivative_all, RealRooted.splits_C_mul_add_derivative, Polynomial.Splits.derivative

Operation

Image under a real-rootedness preserver

{
  "index_shift": 0,
  "operation": "preserver_image",
  "operator": "{\"shape\":\"derivative_polynomial\",\"coefficients\":[{\"numerator\":[\"1\"],\"denominator\":[\"1\"]},{\"numerator\":[\"1\"],\"denominator\":[\"1\"]}]}"
}

Premises

a(n) = 1 if n is a triangular number, otherwise 0. (sequence)
uses: Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]

Claims

{ "claim": "real_rooted", "from_index": 0, "region": { "upper": { "closed": true, "value": "0" } } }

Verification and certificate

polytool: replayed (the certificate replayed when the step was written)
Lean: not attempted
certificate: preserver_image, SHA-256 7602bd06652b845cec76b08d932c9e0f0ac0b855e49647c3babbc5d9117d4091, 6,180 bytes (1,760 compressed); download JSON

Cited by

n-39194b37db596ae8 (real_rooted)
n-39194b37db596ae8 (one_signed_coefficients)
n-39194b37db596ae8 (hadamard_kernel)

References

[SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.

Proof step e-b6c6a979053116b3