A121734 Ramanujan tau numbers such that A000594(k) == A000594(k+1) mod 691, or A046694(k) = A046694(k+1).

483, 209, 21, 632, 650, 541, 546, 281, 666, 440, 397, 576, 18, 251, 356, 207, 532, 361, 121, 642, 288, 167, 348, 505, 561, 0, 108, 166, 97, 492, 58, 255, 632, 151, 679, 185, 141, 587, 0, 549, 459, 428, 549, 157, 559, 121, 605, 102

Offset: 1

Author

Alexander Adamchuk, Aug 18 2006

Keywords

• nonn

Comments

The corresponding indices k are listed in A121733.

Examples

			a(1) = 483 because the first pair of equal consecutive numbers in A046694 is A046694(184) = A046694(185) = 483.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Ramanujan's Tau Function.

Crossrefs

Cf. A000594, A046694, A121733.

Programs

Mathematica

Do[f=Mod[DivisorSigma[11,n],691];g=Mod[DivisorSigma[11,n+1],691];If[f==g,Print[{n,f}]],{n,1,10000}]

Formula

a(n) = mod(A000594(A121733(n)), 691) = A046694(A121733(n)).