A369386
a(n) is the constant term in expansion of Product_{k=1..n} (x^(2*k-1) + 1/x^(2*k-1))^2.
Original entry on oeis.org
1, 2, 4, 8, 18, 48, 138, 428, 1392, 4652, 15884, 55124, 193724, 688008, 2465134, 8899700, 32342236, 118215780, 434314138, 1602935104, 5940303754, 22095769648, 82464791420, 308715131744, 1158949678600, 4362040367048, 16456820491806, 62223707844096
Offset: 0
-
Table[Coefficient[Product[(x^(2 k - 1) + 1/x^(2 k - 1))^2, {k, 1, n}], x, 0], {n, 0, 27}]
A369387
a(n) is the constant term in expansion of Product_{k=1..n} (x^(2*k-1) + 1 + 1/x^(2*k-1))^2.
Original entry on oeis.org
1, 3, 9, 43, 243, 1539, 10557, 75595, 558117, 4218077, 32466849, 253624579, 2005655781, 16024596491, 129159081787, 1048931938309, 8574963650419, 70507361919587, 582730070295737, 4838280518142269, 40336851095845719, 337541054046113077, 2834101218805540871
Offset: 0
-
Table[Coefficient[Product[(x^(2 k - 1) + 1 + 1/x^(2 k - 1))^2, {k, 1, n}], x, 0], {n, 0, 22}]
A369388
a(n) is the constant term in expansion of Product_{k=1..n} (x^prime(k) + 1 + 1/x^prime(k))^2.
Original entry on oeis.org
1, 3, 9, 45, 249, 1373, 9177, 62257, 453179, 3320531, 24087877, 183643865, 1394580343, 10794949627, 85730722969, 686171829489, 5487361175591, 43981108061647, 358362244544957, 2922625435214613, 24006575088945973, 199229783030494775, 1653790732247194785
Offset: 0
-
Table[Coefficient[Product[(x^Prime[k] + 1 + 1/x^Prime[k])^2, {k, 1, n}], x, 0], {n, 0, 22}]
A369389
a(n) is the constant term in expansion of Product_{k=1..n} (x^(k^2) + 1 + 1/x^(k^2))^2.
Original entry on oeis.org
1, 3, 9, 35, 141, 745, 3955, 23985, 155527, 1060941, 7393765, 53041015, 387815175, 2882682967, 21715452927, 165583974835, 1275674593889, 9918184576835, 77738274996385, 613753581566079, 4877383708962749, 38989308129231703, 313354624116918229, 2530796548734844153
Offset: 0
-
Table[Coefficient[Product[(x^(k^2) + 1 + 1/x^(k^2))^2, {k, 1, n}], x, 0], {n, 0, 23}]