A193568 Unhappy numbers which enter the cycle (4, 16, 37, 58, 89, 145, 42, 20) at 58.

38, 58, 73, 83, 116, 119, 161, 166, 191, 235, 253, 299, 307, 308, 325, 352, 357, 370, 375, 380, 468, 486, 489, 498, 523, 532, 537, 573, 611, 616, 648, 661, 679, 684, 697, 703, 730, 735, 753, 769, 796, 803, 830, 846, 849, 864, 894, 911, 929, 948, 967, 976

Offset

1,1

Links

Table of n, a(n) for n=1..52.

Eric Weisstein's World of Mathematics, Unhappy Number.

Example

468 is such a number of height 4 because it enters the cycle at 58 in 4 steps: 468 -> 116 -> 38 -> 73 -> 58 -> 89 -> 145 -> 42 -> 20 -> 4 -> 16 -> 37 -> 58 -> ...

Maple

S:=proc(n) local Q, k, N, z; Q:=[n]; for k from 1 do N:=convert(Q[k], base, 10); z:=sum(N['i']^2, 'i'=1..nops(N)); if not member(z, Q) then Q:=[op(Q), z]; else Q:=[op(Q), z]; break; fi; od; return Q; end:
a:=[]: for i from 1 while nops(a)<30 do Q:=S(i); A:=Q[nops(Q)]; if A=58 then a:=[op(a), i] fi; od: print(op(a));

Crossrefs

Cf. A031177, A039943.

Sequence in context: A098126 A244313 A147616 * A039466 A216140 A177044

Adjacent sequences: A193565 A193566 A193567 * A193569 A193570 A193571

Keyword

nonn,base

Author

Martin Renner, Jul 31 2011

Status

approved