A371381 Main diagonal of A219875.
2, 8, 13, 25, 41, 52, 74, 89, 117, 149, 170, 208, 250, 277, 325, 356, 410, 468, 505, 569, 610, 680, 754, 801, 881, 965, 1018, 1108, 1165, 1261, 1361, 1424, 1530, 1640, 1709, 1825, 1898, 2020, 2146, 2225, 2357, 2440, 2578, 2720, 2809, 2957, 3109, 3204, 3362, 3461
Offset: 1
Links
- Paolo Xausa, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
Array[#^2 + Ceiling[# / GoldenRatio]^2 &, 100]
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Python
from math import isqrt def A371381(n): return (n<<1)*(n-1)+1+(q:=n+isqrt(5*n**2)>>1)*(q-(n-1<<1)) # Chai Wah Wu, Mar 21 2024
Formula
a(n) = n^2 + ceiling(n/(1 + sqrt(5))/2)^2 = n^2 + A019446(n)^2.