A372291 Numbers that occur exactly once in the odd bisection of A371094.

45, 69, 93, 141, 165, 189, 237, 261, 285, 333, 357, 381, 429, 453, 477, 525, 549, 573, 621, 645, 669, 717, 725, 741, 765, 813, 837, 861, 909, 933, 957, 1005, 1029, 1053, 1101, 1109, 1125, 1149, 1197, 1221, 1245, 1293, 1317, 1341, 1389, 1413, 1437, 1485, 1493, 1509, 1533, 1581, 1605, 1629, 1677, 1701, 1725, 1773, 1797

Offset

1,1

Comments

Numbers that occur exactly once in array A371100.

Links

Antti Karttunen, Table of n, a(n) for n = 1..25365

Example

45 is present because A371094(k) = 45 for no other odd number than k=7.

Prog

(PARI)
A371094(n) = { my(m=1+3*n, e=valuation(m, 2)); ((m*(2^e)) + (((4^e)-1)/3)); };
isA372291(n) = if(!(n%2), 0, my(c=0); forstep(k=1, n, 2, if(A371094(k)==n, c++; if(c>1, return(0)))); (c));

Crossrefs

Cf. A371094, A371100.

Setwise difference A372290 \ A372292.

Sequence in context: A172466 A038494 A026043 * A330850 A053720 A259218

Adjacent sequences: A372288 A372289 A372290 * A372292 A372293 A372294

Keyword

nonn

Author

Antti Karttunen, Apr 26 2024

Status

approved