login
A226795
Numbers of the form (7^j + 9^k)/2, for j and k >= 0.
1
1, 4, 5, 8, 25, 29, 41, 44, 65, 172, 176, 212, 365, 368, 389, 536, 1201, 1205, 1241, 1565, 3281, 3284, 3305, 3452, 4481, 8404, 8408, 8444, 8768, 11684, 29525, 29528, 29549, 29696, 30725, 37928, 58825, 58829, 58865, 59189, 62105, 88349, 265721
OFFSET
1,2
MATHEMATICA
a = 7; b = 9; mx = 600000; Union[Flatten[Table[a^n + b^m, {m, 0, Log[b, mx]}, {n, 0, Log[a, mx - b^m]}]]]/2
PROG
(PARI) list(lim)=my(v=List(), J, K); lim=(lim\1)*2; for(j=0, logint(lim-1, 7), J=7^j; K=1; while(J+K<=lim, listput(v, (J+K)/2); K*=9)); Set(v) \\ Charles R Greathouse IV, Feb 18 2021
CROSSREFS
Cf. A226831 (7^j + 9^k).
Sequence in context: A352396 A072808 A104884 * A113726 A207191 A240790
KEYWORD
nonn,easy
AUTHOR
T. D. Noe, Jun 19 2013
STATUS
approved