Sequences

Positive integers k such that k | (12^k + 1).

Inverse of 1953rd cyclotomic polynomial.

Numbers k such that k | 13^k + 1.

Inverse of 1955th cyclotomic polynomial.

Numbers k such that k | 14^k + 1.

Inverse of 1957th cyclotomic polynomial.

Inverse of 1958th cyclotomic polynomial.

Positive integers k such that k | (15^k + 1).

Numbers k that divide 16^k + 1.

Inverse of 1961st cyclotomic polynomial.

k is the first integer such that phi(k + n) | sigma(k).

Inverse of 1963rd cyclotomic polynomial.

Positive integers n such that n | (3^n + 2).

Numbers k that divide 4^k + 1, k not a power of 5.

First k>n, not a power of n+1 or one of its prime factors, such that k | n^k + 1.

One iteration of Reverse and Add is needed to reach a palindrome.

Two iterations of Reverse and Add are needed to reach a palindrome.

Inverse of 1969th cyclotomic polynomial.

Three iterations of Reverse and Add are needed to reach a palindrome.

Four iterations of Reverse and Add are needed to reach a palindrome.

Inverse of 1972nd cyclotomic polynomial.

Five iterations of Reverse and Add are needed to reach a palindrome.

Inverse of 1974th cyclotomic polynomial.

Six iterations of Reverse and Add are needed to reach a palindrome.

Inverse of 1976th cyclotomic polynomial.

Seven iterations of Reverse and Add are needed to reach a palindrome.

Inverse of 1978th cyclotomic polynomial.

Eight iterations of Reverse and Add are needed to reach a palindrome.

Inverse of 1980th cyclotomic polynomial.

Nine iterations of Reverse and Add are needed to reach a palindrome.

Numbers such that ten iterations of Reverse and Add are needed to reach a palindrome.

Eleven iterations of Reverse and Add are needed to reach a palindrome.

Twelve iterations of Reverse and Add are needed to reach a palindrome.

Smallest k such that the smallest palindrome > k in the Reverse and Add! trajectory of k is reached after exactly n iterations.

a(n) = (tau(n^3)+2)/3.

(tau(n^4) + 3)/4, where tau = A000005.

Inverse of 1988th cyclotomic polynomial.

Inverse of 1989th cyclotomic polynomial.

a(n) = (tau(n^5) + 4)/5.

Inverse of 1991st cyclotomic polynomial.

a(n) = (tau(n^6)+5)/6.

a(n) = (tau(n^7)+6)/7.

a(n) = (tau(n^8)+7)/8.

Inverse of 1995th cyclotomic polynomial.

a(n) = (tau(n^9)+8)/9.

a(n) = (tau(n^10)+9)/10.

a(n) = (tau(n^11)+10)/11.

a(n) = (tau(n^12)+11)/12.

a(n) = (tau(n^13)+12)/13.

Inverse of 2001st cyclotomic polynomial.