97903

Appears in sequences

• a(n) = a(n-1) + a(n-2) + 1 for n>1, a(0)=3, a(1)=11.at n=20A022410
• Triangular numbers with sum of digits = 28.at n=32A068132
• Concatenation of triangular number k and its 10's complement is prime.at n=25A108970
• Primitive numbers in A229307.at n=39A229311
• G.f.: exp( Sum_{n>=1} A163659(n^3)*x^n/n ), where x*exp(Sum_{n>=1} A163659(n)*x^n/n) = S(x) is the g.f. of Stern's diatomic series (A002487).at n=15A237646
• G.f. satisfies: A(x) = (1 + x + x^2)^7 * A(x^2)^4.at n=7A237647
• Numbers k such that sigma(k)^2 is divisible by k-1.at n=44A344347