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A355714
Numbers k > 0 such that A090252(A355176(k)) does not equal prime(k)^2.
0
1, 2, 16, 26, 32, 35, 40, 59, 60, 69, 92, 105, 110, 112, 113, 137, 167, 169, 178, 185, 186, 188, 207, 210, 260, 261, 274, 287, 289, 342, 344, 346, 356, 357, 359, 361, 362, 363, 391, 412, 417, 434, 457, 477, 478, 479, 480, 481, 492, 547, 563, 598, 663, 666, 671
OFFSET
1,2
COMMENTS
In contrast to A354169 (a set theoretic analog of A090252) where we observe many as yet unproved regularities, in A090252 the situation appears to be more complicated. This sequence is intended to help spot these irregularities and perhaps lead to further rules, which probably have no analogy in A354169.
In most cases A090252(A355176(n)) equals prime(a(n))*p where p is prime. Surprisingly p is in many cases greater than prime(a(n)).
Is this sequence infinite?
FORMULA
A090252(A355176(a(n))) <> A000040(a(n))^2.
A000040(a(n)) divides A090252(A355176(a(n))).
A000040(a(n)) divides A090252(2*A355176(a(n))+1).
CROSSREFS
KEYWORD
nonn
AUTHOR
Thomas Scheuerle, Jul 15 2022
EXTENSIONS
More terms from Jinyuan Wang, Jul 15 2022
STATUS
approved